The definition of ‘pop star’ in the Collins English Dictionary is unambiguous: ‘A famous singer or musician who performs pop music.’ Well, that seems fairly self-explanatory, doesn’t it? It also seems way wide of the mark, because being a pop star (or a rock star, its longer-haired cousin) encompasses a great deal more than being famous for singing pop songs. As Nik Cohn wrote, describing the first flush of idols of the rock’n’roll age, they were ‘maniacs, wild men with pianos and guitars who would have been laughing stocks in any earlier generation… They were energetic, basic, outrageous. They were huge personalities and they used music like a battering ram.’

Or consider this line from David Hepworth, about Ian Stewart – who helped found the Rolling Stones, and was then dumped by them for not looking the part. ‘He could never have been a rock star for the same simple reason that the rest of us aren’t rock stars. Because we can imagine not being one.’

All this came to mind watching Brett Morgen’s film Moonage Daydream, about David Bowie, for if anyone encompasses the concept of the pop star, it is Bowie. He would have been a laughing stock in any earlier generation. He was energetic and outrageous (if not basic). He had a huge personality and used music like a battering ram. And very few of us could imagine being him. Oh, and he was a famous singer or musician who performed pop music. But where are the pop stars now?

Maybe pop stars have gone for ever – the pair of words has become meaningless, used to describe anyone who happens to make pop music (this time last year I went to the London headline show of an artist described in one daily newspaper as ‘the breakout pop star of the summer’; there were maybe 40 people there. I don’t think that person could accurately be described as either a breakout or a pop star).

There are people who should be pop stars. Charli XCX certainly exists like one, without ever quite achieving the monstrous worldwide fame that should surely be a prerequisite of actual stardom. Matty Healy of the 1975 both talks the talk and walks the walk, but his band still seem to be a huge niche concern, rather than globe-straddling titans of pop.

True pop stars – people who are recognised by people in all age ranges, who can get into newspapers without really having done anything, who live lives unimaginable to the rest of us and who continue to command loyal audiences – are few and far between: Beyoncé, Rihanna, Harry Styles, the members of the K-Pop band BTS, Taylor Swift, perhaps some of the post-Disney stars such as Ariana Grande, but not many others.

Contrast this with the days of, say, Band Aid, and imagine getting that many people in one room, almost all of whom could legitimately be called pop stars. It just wouldn’t happen. It just couldn’t happen, because those people no longer exist.

Part of this is a matter of metrics. Can you even be a star if no one knows how successful you are? A decade or so ago, I tried to write a piece about how the music industry was measuring success. I couldn’t, because no matter who I spoke to – managers, artists, publishers, label bosses – no one knew how to measure success any longer. The charts – the official measurement for those of us who remember music before downloading and streaming – are now all but meaningless, easy to manipulate (look at the number of groups who mobilise their fans to get their album to No. 1 in the week of release, only for it to plummet the next week), or with singles charts subject to the vagaries of multiple tracks from one album cropping up simultaneously.

Streaming figures don’t help much, because they measure only the popularity of a particular song. Live attendances are no guide, because the biggest live shows – with a few exceptions – tend to be old artists playing the hits of decades ago. Many record company talent scouts now choose to hunt new artists in data rather than at gigs in the backrooms of pubs – looking at social media follower numbers, and momentum on streaming platforms. This highlights another problem. Nascent pop stars aren’t competing with each other so much as trying to grab some attention from those drawn to Instagram influencers, YouTubers or TikTokkers.

That need for a constant presence on social media – something artists have started to complain about – has also destroyed the alienness of pop stars. Over the past decade or so, relatability has become far more important than exceptionalism – someone who tells you what they had for breakfast, and makes everyday observations about the world, is unlikely to turn themselves into the new Bowie or Bryan Ferry, or even the new Simon Le Bon.

And relatability signals vulnerability. These days, musicians’ behaviour and statements are scanned – for signs of being a wrong’un, for mental health problems, for anything wrong. Were a musician today to behave publicly as Bowie did in the mid-1970s, for example – starving himself by living off cocaine, milk and peppers, keeping his urine in the fridge, giving Nazi salutes at Victoria station – Twitter would be awash with people wanting them to seek help and sort themselves out.

But the main reason for the disappearance of pop stars, in the UK at least, is a functional one. We have lost the principal means of dissemination of information about them: Top of the Pops. If you look on Twitter on a Friday evening, you are very likely to see some half-forgotten star of the past trending, and that’s because a chunk of people are watching a repeat of TOTP on BBC4 and are reliving their past. In the days of Top of the Pops, the simple fact of the entire family seeing the biggest pop stars of that week in one place meant we shared a language about popular culture. No longer, alas.

It lessens the gaiety of nations to be without pop stars, those ridiculous peacocks with their will to musical power. Rather one Brian Connolly of the Sweet, or one Nick Rhodes from Duran Duran, than a thousand drearily earnest young singers talking about their self-esteem problems. Pop stars made us feel that they were too large for this humdrum existence, and that by taking us with them, we could become large too – we could be heroes, just for one day. Now they want to be the same as us, and where’s the fun in that?