Probably a stupid question, but, I've been using Thunderbird to d/l my gmail for ten years with POP3, leaving nothing on the server. I don't store a password on my device, I remember it and enter it. I don't use 2FA, because I consider simjacking a risk; my personal email server is my backup address if I get locked out of gmail.
I suppose this means that no part of this strategy viz-a-viz gmail, Thunderbird and POP3 is going to work for me anymore..? The good news, I guess, is I won't lose any mail. The bad news is, gmail users have recently started to get email from my private server to their spam, occasionally, even though my IP's nowhere near a blacklist and hasn't been for years; thus, being able to send gmail-to-gmail has been helpful sometimes.