People should be using email alias. 1 unique alias per 1 uniques service and websites for proper segregation. If any of the unique alias leaked or getting spammed you'd know where the source is and blocking that specific alias would limit the breach. Theres simplelogin.io, addy.io, firefox relay, apple hide-my-email, custom domain catchall etc for that.
If Gmail goes down in 20 years, it will be a major occurrence. If mailgoforward.fart goes down, you’re screwed.
The advice is, as always, use a second mail address for “sensitive” providers. Use a password manager and two factor for everything. Ideally one that integrates into your phone and browser.
For traceability, most providers support a + alias syntax now. Ie foobar+baxservice@provider.com