From Spanish Govt. website that has not been updated since 2020:
“At the request of the competent authorities, the traveller must present proof of having sufficient financial means for the proposed stay or of the ability to legally obtain such means.
In 2020, the minimum amount required is 90 euros per person per day. In any case, and regardless of the length of stay, the traveller must have at least 810 euros or its equivalent in foreign currency.
Economic means may be accredited by presenting cash, traveller's cheques, a credit card accompanied by a bank account statement, an up-to-date bank book, or any other resource that accredits the amount available, such as a credit statement regarding the card or bank account. Bank letters or online bank statements will not be accepted.”
www.exteriores.gob.es/Consulados/Manchester/en/ServiciosConsulares/Paginas/Consular/Condiciones-de-entrada-en-Espana.aspx
So this isn’t anything new, just the amounts have been increased.
I’ve been going in and out of Spain all my life (Father born in Spain) flip-flopping between two passports. I’ve never had to prove funds availability. Nobody I know has ever mentioned having to do so. The third paragraph above tells you what to bring if you need peace of mind.