I've been to a fair few Bundesliga games and agree completely about how things are done better over there. Standing, drinking, free public transport, cheap ticket prices... the list goes on. But then the German ownership model is of course very different (better) than here, and fans are considered a much higher priority. If we want the same results as Germany, we have to adopt all the same approaches across the board. I saw the Accrington chairman said he doesn't want to have to pay more for police and stewards to solve the problem as that just adds onto the ticket price. We already have a situation where watching League 2 football costs more than top sides in the Bundesliga, so ultimately more stewards and more police will punish the 99% of innocents by making them pay more whilst feeling like they need supervision.
So I think you're right, that part of the solution is to throw the book at the offenders who cross the line and assault players (the crossbar breakers need a slap on the wrist too). The problem is, we're also in a situation where players, club staff and officials will be fearful of getting whacked as soon as a final whistle has gone, which is simply not on and does no fan any favours, so it really needs fans to self police and ostracise those that cross the line. The other issue as I see it (which is along the lines of what
@Big Ron has said) is that the whole thing sets any progression around how fans are portrayed further back, because the powers that be will simply say 'oh look, they can't behave, how terrible, stick a cage round them and charge more so the idiots can't afford to attend.' And the solution to that is fan groups advocating on behalf of fans to try and open up proper conversations with the powers that be, because if we all just shout 'cancel culture!' at them, then it's an easy way for the big powers that only care about TV rights and global brand to construe that we all think spear tackling the opposition centre forward is fair game.