I receive email on my domain, which means that it is the root of all of my security. If you steal my domain or tweak my DNS, you can get my email, and you can reset my passwords.
I have some domains at Namecheap still. I have a FIDO2 key set up for their website, which is good, but I’m not sure that I trust their security. I trust Google more.
Google Domains actually has support, too