This page has some more information about the drawbacks/weaknesses of SameSite, worth a read: https://developer.mozilla.org/en-US/docs/Web/Security/Attack...
You usually need another method as well
You usually need another method as well
In practice, SameSite=Lax is already very effective in preventing _most_ CSRF attacks. However, I 100% agree with you that adding a second defense mechanism (such as the Sec header, a custom "Protect-Me-From-Csrf: true" header, or if you have a really sensitive use case, cryptographically secure CSRF tokens) is a very good idea.