Yeah, the recent timelines seem to be roughly:
11 months from "we received your application" to acknowledgement of receipt (AOR)
+ 3+ months to "we started processing" (I'm at 3½ and counting)
+ 1 month to "we sent your citizenship certificate"
=
15+ months total, which matches IRCC's estimate at
Check processing times > Citizenship > Citizenship certificate
Even worse, it's actually
19½ months total if you count the time, as of November 9, 2021, from where IRCC is "finalizing most applications we received between March 22-28, 2020" at
Check your application status > Citizenship > Citizenship certificate > Online or By mail, no difference