Most online accounts are tied to my email as an id. Suddenly losing my gmail would mean losing those accounts too. I'm fairly certain I could recover eventually, but it would be a disaster.

The message archive is not a consideration.

Switching to another service is definitely indicated, but it would be months of toil to migrate all the aforementioned accounts.

> but it would be months of toil to migrate all the aforementioned accounts.

It took a year for me. The sooner you start, the sooner you're done with it