Here in turkey we no longer switch DST since 2016 . We are use to it now but at first the longer darker mornings in the winter was a concern as most schools start at 8am - 8:30am and for a few weeks sunrise due to we don’t change was 8:40am .The concern obviously children going to school in the dark . Other side effect is computers ,products and other functions that are programmed or rely on timezones based on DST this will give you a headache big time until the manufactures or developers release a fix .
Summer no real difference but winter you notice it.
It takes a while for electronic devices to play catch up but eventually it gets done. Still some of our things like watches digital types which automatically still switch due to internal programming, my beloved 8 year old Casio pro trek watch calculates the time based on selecting Istanbul which is programmed internally to use dst so I have to use Baghdad believe it or not or Moscow . It’s these little devices and some others we have around the house like our cable tv box which wasn’t updated until recently that was always an hour out October onwards .
As for websites php timezones will be out until a fix is released still I’m using Baghdad as a timezone for Istanbul Turkey as the hosted server I use still thinks turkey uses dst .
So if it happens expect some teething issues at the beginning..