It can be "seasonal". Sometimes an airline decides they have a problem and go nuts. Check the flyertalk forums for mainline airlines before going.
I had Air Canada weigh my hand luggage at the business (!) check in (this was either YVR or YYZ) and insist I get both of them under 10kg despite the combined weight was under 20kg... Then they stopped this foolishness, it lasted a couple months. I think they even changed the rules so now it's just "you need to lift your bag" instead of "10kg".
I had American Airlines at one airport (sorry, too many years, too many airports, for my life can't remember which) have agents at the foot of an escalator leading to check in / security everyone caging their carry ons, tagging those that pass and there was a lot of anguish about this. This also happened only once.
I had British Airways at one point having people line up at the entrance of the gate (again can't remember which airport but it was IMO in Europe) and they caged everything and they didn't let in anyone to the gate area if it didn't fit. They even charged (heavily) for bags that didn't fit. It wasn't fun. This was a campaign of sorts of theirs, lasted a few weeks.
Low cost is different. Wizz Air always caged at Budapest, never at Luton. I frankly lost count how many times I did that in the last uh seven years or so. Bu then again they just changed Budapest airport so I am less sure. Especially because buying priority on these airlines not only allow you to carry two bags but makes you exempt from the blanket caging. I guess if you showed up with a 30" suitcase and tried to carry it on you'd be stopped but eventually you need to lift it up and put it in the luggage rack or underseat and if you can't you need to check it in anyways so there's a point where all this is futile.