Does it make sense to filter the form on the client?

Question

Validation

Hello colleagues!
Does it make sense to filter the form on the client?
After all, it's elementary to bypass validation on the client. Well, what's the point of her? Wouldn't it be safer and more correct to do form validation and filtering in PHP (that is, on the client side)?
Thanks in advance to everyone who answers.

Answer 1

Validation on the client is done only for responsiveness and improving the user experience.
This does not cancel or replace validation on the server.

Answer 2

I present registration in some social network without preliminary validation of the login for uniqueness...