I worked as a bouncer, in the UK, and IDing is pretty common, both at the door and at the bar. If you look over about 25, you’re unlikely to be asked, but my 21 year old friend certainly got asked to prove his age last time he went to the pub with me.
Standards have definitely got stricter in recent years as well, I actually got asked for ID more in the year when I was 24 than when I was 17.