Safe standing is the norm in Germany- behind both goals for home and away fans (though the away part is smaller). I am not sure about capacities though. I saw somewhere that the infrastructure for safe standing means that the capacity is about the same but even then, the fans crowd together and there are gaps at the back and sides. It certainly helps with the atmosphere though. I was at Eintracht v Mainz and it was quite something....except the Germans can't sing.
If you want Safe Standing here is a petition to support it - https://petition.parliament.uk/petitions/207040
I don't need the weather forecasters to tell me when rain is on it's way, my knees do that for me. My right knee has no cartilage left, they do like to click all the time.