After trying to understand why my moltbot (or openclaw) couldn't delete my unwanted newsletters, I figured out that it is trying to use the batch delete operation.
However, gog uses the gmail.modify scope when authenticating.

The documentation (https://developers.google.com/workspace/gmail/api/auth/scopes) says for https://www.googleapis.com/auth/gmail.modify:

All read/write operations except immediate, permanent deletion of threads and messages, bypassing Trash.

Quick fix: Maybe gog can also add a non-batch delete that essentially just does "gog gmail labels modify <threadId> --add TRASH --remove INBOX".
(I did tell my bot to do it like that and it now deletes emails)