Same. It may lack encryption that many look for, but I have accepted that email is too old to ever be truly secure. Most email is either coming from, or going to services provided by big tech companies anyway. I prefer an open, fully standards compliant email service over a locked down service that provides minimal additional security.
I agree that Kagi isn’t great from a privacy perspective. But in regards to clearing cookies, they do have a session link feature that uses a token to avoid the need to sign in all the time.
Proton will still be a for-profit company that will be majority-controlled by a non-profit. The non-profit will not own all of the business either, so there will still be profits going to shareholders.