Keep in mind the Hikvision and Dahua and their OEMs of the world make their money on the front end, so they have no incentive to continually provide firmware updates. If you see 3 updates in the life of a camera, that is a lot and those are usually in the first year or so.
Even high-end Axis only guarantees updates for 5 years. Granted that is more than most, but don't expect updates.
Further most here do not update if the camera is working for our needs. Most of the updates are for security vulnerabilities, but if you don't allow your cameras access to the internet, then it doesn't make sense to update. We see too many issues from people
updating just for the sake of updating.
If you want updates, that is what a new model is for.
If you want stuff updated, then you need to go to consumer grade crap with subscription services, but even then they will EOL stuff at some point.