Yeah there doesn't have to be, though. I would say the combat system in Destiny kicks the crap out of the combat system in Fallout. And you're right - I noped out of Skyrim maybe ten hours into it. Same with Monster Hunter. I much prefer the Japanese obsession with fishing to the American obsession of "we're going to turn this thing into a dice throw". And there's definitely a place for "I want adventure, sights and sounds but I don't want to leave the couch." My video gaming is entirely limited to "thing that I do on the couch next to my wife who is reviewing charts." So many video games are "learn best how to cheat our shitty mechanics." That's Skyrim in a nutshell. There's also a real tendency to "figure out how best to advance your character to beat this thing you can't get past that you won't know about for another 30 hours of gameplay" (Persona 5, Destiny's last DLC, Witcher). I read somewhere that Bungie's theory was that any game should be playable within 10 seconds of picking up the controller. Certainly how I got hooked on Destiny. HZD is similar; Guerilla definitely learned a lot from what made people stop playing Killzone:Shadow Fall. Just because "real life" will always be more interesting than "video game" doesn't mean that the video game shouldn't strive to be interesting. And that's the problem, really - the walk isn't worth the haphazard combat. I once spent 20 minutes walking to a weird ass corner of the HZD map because there were alligators there.but you're absolutely right in that there are compromises in how they're put together.
In my opinion, games like Fallout 3, 4, The Outer Worlds, Skyrim, etc. are best viewed as "walking simulators with combat haphazardly slapped on."