Opening a French bank account isn't complicated either if it is with a multinational bank, I have never been inside a French branch of mine.

You cannot use a bank accounts well across EU country. Banks are a very localized service, they provide specific account number formats and payment methods by country. It will be a huge hassle day to day when you want a SEPA transfer and the guy expects a RIB or a sort code.

It's worse with UK and Switzerland because they have a different currency. You really need a local bank account or you get bankrupted by the fees and the exchange rate. Incidentally they are the only places where there are the big tech and finance companies to work for.

Most banks are national. There are very few banks that have an international presence, with decent service at the offices.

The last time I went to a French bank in a different region than where I opened the account, they told me they can't do anything and I have to go to my "home" agency.

And all bank transfers within the EU (not sure if the U.K. is a special case) are free of charge, and IBAN/BIC used everywhere. I routinely transfer money between my Austrian and German accounts.