Not just La Caixa. BBVA as well. Probably being a cartel, the others too. The two I'm mentioning not just block SEPA transfers to exchanges, they won't even allow card payments to exchanges.
Wise, which used to be my solution to that problem, no longer allows SEPA transfers either, but at least they do card payments.
To me it's very obvious that they're doing this just as a warm-up for them to start to offer their own paper BTC scams (which they will misrepresent as "safe products").
Very soon the only real option to buy real BTC will be Bisq, which I love but has a lot of associated inconvenient points.