Android is only recently switching to quarter releases instead of yearly. Most. Popular Linux distros only have major releases every 6 months. While chrome cuts a release branch every 4 weeks, it soaks it in a beta channel for another 4. Same goes for the rust compiler toolchain, albeit on a 6 week cadence.
It’s more common than you think if you expand your view of release a bit. On the one hand you very much still have shrink-wrap software (for example, all firmware) that ships on a very slow cadence.
On the other hand even the big tech companies will only expose code paths very slowly and very conservatively. Meta’s Threads.app for example combined both a constant churn of innovation on master with a very measured gating of new features shipping to the public.
The best teams do indeed, as you say, ship and test finished builds on a weekly or daily basis even if the stuff that gets under the customers’ / users’ / clients’ noses appears on a far less regular basis. After all, any kind of severe bug could necessitate a release at any moment.
not all the world is a web site or even internet connetted. not all the world has no safety concerns.
if you work in medical or aviation areas every release legally needs extensive - months - testing before you can release. If there are issuse found in that testing you start over. Not all tests can be automated.
i work in agraculture. the entire month of July there will be nobody in the world using a planter or any of the software on it. there is no point in a release then. the lack of users means we cannot use automated rollback if the change somehow fails for customers - we could but it would be months of changes rolled back whe Brasil starts planting season.