perepelov

I was on AC834 yesterday from YYZ, it landed on time at YUL (7pm), then the captain went on the PA to say that there will be "five to ten minutes" before we get to the gate. 15 minutes later - another announcement: "They just told us it will be another 5 minutes". We finally got to our gate at 7:30 pm, 1/2 hr after landing.
This happened to me previously many times at my home airport - only this time I was sitting next to two AC Rouge FAs. Who were very talkative. I wasn't in any way eavesdropping - but it was impossible NOT to hear what they were talking about, for me and people in at least two rows both directions.
From their conversation, I gathered that they were assigned to a flight that was leaving shortly - at some point one of them said "the check-in is in 10 minutes, and we're not even at the gate". They called their helpdesk several times (I memorized the codes they used btw - so great job on protecting sensitive data) and were told to "just go to the gate" - meaning there was no backup for that flight. According to them, the airline was going to delay the flight because of them - and pay a penalty for that. "That just shows how short-staffed they are in Montreal" - finally said one of the FAs.
So, is Air Canada really experiencing shortage of human resources at their main hub? And if yes - that why would that be?
I just checked, and it seems that the company is doing relatively well from financial standpoint, even boasting "a record number of passengers" last year. So it definitely has funds to be invested - in order to improve customer experience, for example, reduce the time of unnecessary delays like the one I was in. Then why is it not doing it?