my general approach to this garbage is to just keep making new accounts/email addresses (on my domain) for each purpose
this keeps everything from being comingled at the expense of maintaining all of those credentials
also, as a bonus, if you organize this by subdomain you can sort your email by it automatically since most emails from this stuff don't really need to hit your inbox
Until they ban all of your alts when some obscure ToS sentence about creating multiple accounts starts being enforced (or one of them gets taken over when you don't pay close enough attention) and if you happen to use any of them for anything critical you come to HN complaining how MS just killed your life or business. I truly think that's what happens behind the scenes of half of those cry for help posts
this keeps everything from being comingled at the expense of maintaining all of those credentials
also, as a bonus, if you organize this by subdomain you can sort your email by it automatically since most emails from this stuff don't really need to hit your inbox