IMAP is both excellent and, annoyingly inconsistent so it's much more of a pain to develop reliable parsers for. I'm pretty happy to use IMAP generally, but I'm also... MODSEQ is wrapped with a () in some places, not but STATUS HIGHESTMODSEQ:

  . SELECT INBOX.Archive
  * 1239 EXISTS
  * 0 RECENT
  * FLAGS (\Answered \Flagged \Draft \Deleted \Seen $X-ME-Annot-2 $HasAttachment $IsNotification $IsMailingList $NotJunk $CanUnsubscribe)
  * OK [PERMANENTFLAGS (\Answered \Flagged \Draft \Deleted \Seen $X-ME-Annot-2 $HasAttachment $IsNotification $IsMailingList $NotJunk $CanUnsubscribe \*)] Ok
  * OK [UNSEEN 1221] Ok
  * OK [UIDVALIDITY 1108730350] Ok
  * OK [UIDNEXT 2231] Ok
  * OK [HIGHESTMODSEQ 40306873] Ok
  * OK [MAILBOXID (210306ee-5833-456b-bede-6d04757128b3)] Ok
  * OK [URLMECH INTERNAL] Ok
  * OK [ANNOTATIONS 65536] Ok
  . OK [READ-WRITE] Completed
  . FETCH 1 MODSEQ
  * OK [HIGHESTMODSEQ 40306873] CONDSTORE enabled by FETCH MODSEQ
  * 1 FETCH (MODSEQ (39570709))
  . OK Completed (0.000 sec)

And... the * operator ranges.

  . FETCH 2231:* (UID MODSEQ)
  * 1239 FETCH (UID 2230 MODSEQ (40306872))
  . OK Completed (0.001 sec)

Source: have also implemented both client and server side IMAP, and reviewed RFC9051 very closely.

So it is just coincidence that there are zero good IMAP clients out there? I have tried a lot of clients and nobody has managed an implementstion which is works well in practice.

And it is a pretty bad query language compared to something like SQL.