Maybe if it’s just two countries right now, but if this ban would become EU wide gaming companies would have to care.
They could just block the EU region and publish to other countries instead. Plenty of games, especially from Asia, already block all EU countries from playing. Usually they're looking to sell a license or don't know how to enter the market. Nevertheless, they are absolutely willing to block the EU region.
I see so many Europeans repeating the line that if Europe regulates X together, then companies will have to care, because they can't ignore the European market. This might be true in other industries, but it's not true in gaming. I would even say that it's more common for the European market to be treated as second class than not when it comes to online games.
Also, it's not about the children. Children don't make their own money - they only have money that parents give them. Even if these games banned children from playing them, a lot of the people complaining about it still wouldn't stop. The problem for them is that they can't make their friends stop playing these games, so they want the government to stop them instead.
I don't like when games monetize stuff like Diablo Immortal does. I hate it. But I'm certain that when legislation does arrive it'll be broad enough that other stuff gets caught up in it and the people advocating for it will just shrug their shoulders and go "lol i didn't care about games anyway".