I’ve heard this being mentioned in the privacy community, but I don’t understand what kind of benefits you get with that.
Assume I’m using name.surname@protonmail address for personal stuff that is connected to my name and an alias service for junk.
What’s the actual benefit of getting a custom domain? When you buy a domain, I believe you need to provide information about yourself. Is that going to be publicly available? Are there ways to protect it?
Most TLDs and domain registrars mask your private details, which means they will not be publicly available.
The biggest benefit of your own domain is control – if you need to switch hosting providers (for email, jabber, sip, website, mastodon, etc etc) instead of creating a new “account” on another service and sending your new address to everyone, you can move the domain to point at another provider and keep your address and contacts, etc.
Think of owning your own domain similar to local number porting for phone numbers, but a lot cooler and more powerful.
To answer some of your questions; Yes you do need to provide information in order to register a domain. Although, you can use a privacy-focused provider like njal.la (discussion about it) where no personal information is required (except your email to login) as they register the domain under their information. One of the main downsides to this is it is quite expensive compared to mainstream registrars and they technically own the domain but, they give all the ownership rights to you and you can transfer the domain away at any time.
If you do want to use a mainstream registrar, most of them offer a free ‘Whois Cloaking’ or ‘Whois Privacy’ option which will hide and replace your information as their own. The registrar will still have access to that data, but it won’t be publicly available.
Hope this helps 