I have bitched and moaned for quite a while about Gmail providing "searching, not sorting". True also of many Google (web)apps.
Sure, Google usually has good search.
But sorting is often the easiest way to go through a pile of stuff. Sort, and then look for, e.g., many emails from the same company that you no longer have an account with.
Anyway, I have bitched and moaned about the lack of sorting in Gmail.
And today I realized ... I can just use Thunderbird via IMAP to access by Gmail account. Thunderbird has sorting. And, in a few hours, I have been able to get rid of several thousand emails.
Actually, this is not the first time I have realized this. But when I tried it in the past Thunderbird regularly hung in annoying ways. Also, IMAP folders did not map wekll to Gmail labels. It appears more reliable now. Moreover, I am no longer trying to use Thunderbird for all of my Gmail - just for this sorting and clearing a lot of stuff out. Archiving. Deleting.