I agree with your statement, and cursive has extra benefits like leading to better hand strength and so on but outside of that, signatures aren't a good counter argument.

Signatures aren't cursive, they're a curated, custom art piece.

Arguably even signatures are being replaced with digital agreements. Just click "I Agree [and we'll use other proof than the squiggly that it was you because your digital squiggly is uselessly different every time]".