Pardon me if I am wrong, however, I am looking for an answer for my understanding that isn't the concerns regarding CSRF solved by both Samesite cookie and Same-Origin-Policy effectively? Then why is the need for 2 different things?
The basic difference which I can recollect:
Same-Origin-Policy (SOP): Is a policy set by the browser to protect a user from not letting it read the contents of another site unless the origin is same or CORS is implemented effectively
Samesite Cookie: On the other hand a job done by a server to mark a cookie to be strict or laxed as per their requirement
Is it just this? is there really a good reason behind having two different ways to prevent CSRF attacks?