Look... we all go through our LTT phase.
I would strongly recommend ACTUALLY looking at what modding a Framework or a Steam Deck would mean. The latter has a decent number of controller mods and varying levels of jank regarding their cooling or storage.
But, at their core, both are more SOC than not. Theoretically, you can replace a USB controller if you break the port but they aren't devices where you are making heavy changes and the Framework upgrade model is to literally buy a whole new motherboard (and, depending on the model, you have to do that for RAM too....). I think the Level 1 Techs review was probably the best where Wendell acknowledged that he would configure his laptop (basically what USB dongles and keyboard layout) once and the rest was just an excuse for him to goof off during a meeting.
Regarding security, you do have a point, although I could always bring my current laptop with me alongside the Steam Deck - I’d just prefer not to because of increasing the weight in the backpack I have to lug around each day.
You know you. But my experience from back in uni is that carrying a gaming handheld was pointless. if I have free time between classes I am going to do my homework or hang out with friends. And once classes are over? I am going home (or to hang out with friends again). And I commuted. For folk who actually live on campus there is even less reason to carry a gameboy around.