I’m relaxed about the down round. All banks valuations have fallen. The fact that Revolut got the value it did at it’s last round is probably more down to timing.
If you want to make money on shares in a bank faster than maybe setup a Freetrade account and buy some shares in some of the older incumbent banks. In the short term they will probably return more. In the long term of course, I would expect them to continue to lose share to the fintechs.