The thing is why do they have to do so? In terms of bargaining power, Apple has the best position comparing to other cell phone/ iPad/ PC vendors. Their software are way more memory efficient than the competitors (like Windows 11 with all the bloated Electron/ Webview2 wrappers).
Bloated Electron / WebView wrappers also tout the feature of running on macOS - and many are forced to use such apps on the mac too ... what then? Apple deciding how much RAM is "enough" for you is based on the use case it has decided for each category of the device. If that isn't sufficient for you, you are supposed to buy the more "premium" edition, even if your use case for that is rare. Imagine if you suddenly need more RAM for a popular app 2 years down the line but you can't really do anything on a Mac now a days because the RAM is soldered and fixed. Buying upgrade-able RAM is obviously much cheaper, and much better for the environment, than buying a whole new device.