I think that's common in Switzerland. They call it 80% contracts.
Similarly in Norway.
It's "sort of" what I've done, only last time I changed jobs I told recruiters it'd take 20%-30% more for me to come into the office full time, and pro-rated below that.
I just straight out reject any onsite. No money would ever bring me back.
I'm told it's a legal requirement for companies to provide that on request here in Germany, though I've never actually tried that yet, don't know any caveats.
I would too but only after I raise my base rate by 25%. If I'm on a salary and have project deadlines it's the same thing anyway.
This is very common in the Netherlands.
And would you work as much unpaid overtime as you would with a salaried 5 day work week job when pressured to by your boss, owner and peers?
That is what it would devolve into.
I never have been pressured by my boss to do unpaid overtime.