As somebody who manages a piece of software often used in wii modding: ye, do it! Mod a wii :p

But seriously, the ps3/wii/x360 era were the last gen where the hardware design was rather simple and easy to understand, making it fun to play with and learn. The wiiu ended up with a bootrom making it harder and way more complex to run your own stuff on it ( outside of wii-mode and non-system menu stuff ). Then the switch was a whole new level (and we got lucky there with the bootrom exploit).
Switch added secure bootrom, executable validation, firmware blobs, no-execute memory flags, dedicated crypto hardware in cpu with it's own firmware, more secure mmu mapping, ...
Even if you had raw access you still needed to implement some stuff just get hardware even going.