*I see a LOT of it around and it always looks awful. It might start off only looking slightly, subtly awful, but it gets worse.
Once people start having it, they keep having it, and they have more and more, and by the time they're in their 60s it has gone horrendously wrong*
There you go again, the UK expert in badly done fillers. However, the ones you see that look bad are where it's badly done, over done etc. Those who have it done well don't look over done and I very much doubt that you'd know. Of course you're going to say you will, because you don't have experience of seeing those, don't recognise those.
I have friends in their 40s and 50s who start having it and it looks sort of OK (although always a bit odd and artificial and shiny and every single one of them has that weird smooth upper lip/philtrum thing) but as time goes on, it really messes up their features
Proof right there that you don't know what you've talking about. The people with shiny, artificial looking face have generally had too much botox, not fillers. The weird smooth upper lip/philtrum is a result of lip fillers specifically.
So I guess what you're seeing on your 'friends' and the people in your area is overdone botox and lip fillers. There are lots of other areas for fillers. It's been discussed up thread why fillers are not placed in marionette lines or around lips ideally.
Again then, proving that you don't know what you're talking about and have no real advice to give. We all know not to overdo it, not to go to inexperienced, unqualified and unethical practitioners. Some choose to do this anyway and the results speak for themselves. Done well, it's a different look entirely.