Thing is you can dilute the questing/missions in both games down to bare bones simplicity and levy that as criticism that ultimately amounts to subjectivity as context and reward are something the player has to find themselves. MGSV missions are literally just "go to place, sneak in, kill/extract dude or blow stuff up, repeat". Wild Hunt is "go to objective marker, talk to person, activate detective mode, follow trail, click things". All games can be distilled down to their basic gameplay loop, but I feel what's important is the details that imbue this loop with interesting context.
In Wild Hunt that context is mostly the writing and world building. If you're not invested in the world itself, the stories being told, the people, the monsters, the lore, and the adventure of Geralt, then yes the quests will be boring as shit.
In MGSV it's the game systems, the stealth, the combat, overcoming the AI, implementing your tools and gear, and maximising your strategy for the biggest gameplay gains in a single mission arc. If you're not invested in the game systems then of course it's repetitive and boring.
Ultimately it's very subjective since neither game will cater to all tastes. But I also feel both games enrich their gameplay loop with enough context and depth to be rewarding for those who have a taste for that context or depth.