You still get some tubes in tall sidewall tyres especially if they are going to run low pressure on agricultural vehicles, but very rare on road vehicles.
You also need to understand that tyres are made in common sizes. It is a frequent mistake to think you can just go a size wider or profile lower as such size tyres simply may not exist. In particular tyre sizes that might have been available 20 years ago are no longer viable to produce. While the most common tyre size is still 205 55 16, the entry level size of a tyre these days starts at 17". Even the Toyota Aygo, which 10 years ago was a 14" size is now 18" on the Aygo X even though the car is essentially the same.
it seems as tho the info i was given elsewhere wasn’t completely helpful shall we say.
its at least reassuring to know kwik fit must still get asked this and they still have to explain it.
have messed around with the width / diameter / profile generators on different sites for longer than i would have liked, i’ve never had any expectation that every w / d / p i’m considering is made, available & in my price range. but you make an interesting point about the trend towards the larger over time.
Lower-profile tyres are pretty stupid given the state of the roads. The manufacturers must all assume we live in Germany, where they seem to iron the roads every night. And they get kerbed much more easily - you see Minis and the smaller BMWs where the rims are so chewed, it’s surprising they hold air.