WE need to calm down a wee bit. Judging by the near-fainting reaction to the Line of Duty finale, millions of viewers must have been watching a different show to the one I’ve sat through for six weeks. Some were in a state of uncontrollable excitement, others were as thrilled as if the Nickelodeon man had turned up in their village circa 1900 to show moving images of trains hurtling toward them, and a fair minority were outraged that the show didn’t live up to their expectations of being the greatest thing on TV since TV was invented.

The truth is Line of Duty is just a rather average – though highly enjoyable – procedural cop show. We’ve been watching this type of series for years – it’s a souped-up Z Cars. It’s cops doing cop stuff as imagined by people who aren’t cops; that’s a well-trodden path. What made Line of Duty stand out was its connecting story arcs for characters between each series, giving the drama a sense of being a real universe with real people in it. That’s where the true investment by the creators lay – the rest could get a bit shonky. On occasions the dialogue was just daft – “AC-12 has a UCO in the OCG’” – and the ending was flagged way too early. You could see the baddie a mile off. The denouement was also all tell and no show. For a series reliant on drama, the unravelling came from exposition not action, and that’s unsatisfying.

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However, I wasn’t massively disappointed. This is what the BBC does well – middle-brow entertainment for the middle classes. Nothing too difficult, or too jazzy. If you arrived at Line of Duty with those limited expectations, then you left feeling pretty happy, if a little “meh”. It was the same with Bodyguard, the other Jed Mercurio show that got the shires chattering as if it was the best thing since Sophocles. It was just-well made TV, nothing more.

Terrestrial TV – “council telly” if you’re cruel – hasn’t got it in it any more to change the way we think about television and popular drama. That job lies elsewhere – and as usual the action is in America, with the likes of HBO, the cable channel behind the real golden age of TV thanks to previous shows like The Sopranos and The Wire, and Game of Thrones today.

There’s real story-telling at work here – deep long-running narrative, characters as morally grey as Gandalf’s cloak, the sense that show-runners have novelists for heroes as the dramas work on a literary level, not just as wham-bam-thank-you-ma’am telly to fill an hour.

Though when you look at something even as revered as The Sopranos – it isn’t really changing the world, either. Yes, it changed television story-telling, but it didn’t make viewers see the world in a different way. There was none of that Dickensian drive to take a story and make it morally alter the world that lies at the heart of all great art.

Game of Thrones is similar – it isn’t taking you to a place of thought, it takes you to a place of gasp. It’s truly spectacular and immersive, its sheer epic scope and stylistic bravura show that TV can challenge cinema for pure visceral showmanship, but aside from proving that women can be as vicious, perverse and morally dark as men it isn’t something which will leave a mark on the world beyond fans basking in an afterglow of “wow”.

Read more: Line of Duty review: A Heck of a finish or a load of old Hooey?

But TV with a greater purpose – drama that wants to change the world – is out there, and that means that art is alive and well, and not totally cowed by the titan Entertainment. Netflix is home to some of the smartest television on the planet. Not only does it serve up a taste of global culture – a sex comedy from France, a horror movie from Korea – but it commissions shows which change how we talk and think about the world.

It became obvious with Orange is the New Black, the women’s prison drama. This wasn’t Prisoner Cell Block H, or even, if you’re old enough to remember, Within These Walls. The Netflix show used the edgy setting of jail to tell the stories of real women – funny women, annoying women, idiot women, clever women – and no-one cared if someone was a lesbian, that wasn’t a big deal. The truth about women’s lives mattered.

Thirteen Reasons Why, a drama about teen suicide, probably gave a greater insight into the mind of the young millennial than any out-of-touch whingeing commentator carping on about snowflakes and safe spaces could ever hope to do.

Right now, there’s a show on Netflix called Special which is going to alter how we think and talk about disability. Special is about a young gay man with cerebral palsy. It’s written by and stars a young, gay man with cerebral palsy. Sounds pretty po-faced and unfunny? It’s anything but – it’s brilliantly dirty, subversive, and hilarious. There’s not an ounce of self-pity in it, and no-one who watches it will ever think of disability the same again. It’s very much a game-changer when it comes to how mainstream society sees the world, in its often limited way.

Britain can still pull out a few shows of import – though, as we’ve seen, not often. Gone are the days of Cathy Come Home in the UK, where drama set the social agenda. However, reality TV – I know, but bear with me – still has scope to shift opinion and cause a conversation. The Great British School Swap on Channel Four – probably the only terrestrial channel left with the talent to commission shows that really matter – threw a harsh spotlight on to race, segregation and intolerance in the UK over the last few weeks. It did what all TV which wishes to matter should do: it held a mirror up to society and asked us to take a good long look at ourselves and how we think, feel and act.

Great TV can alter a viewer for the better, average TV just leaves you entertained but unchanged as a person – except for the avalanche of Wotsit dust that tumbled down the front of your jumper during the ads.

Neil Mackay is Scotland’s columnist of the year.