Guild Wars 2

I’ll call it a ‘bug’ because I want to be nice and assume that no human being actually consciously made the decision to make the conclusion to your grand, epic, solo story a dungeon that requires 5 people and has no difficulty level.
“Butbut zhaitan is too strong to be defeated by just 1 person that’s why you need 4 people”
Destiny’s Edge. Upscale their damage, downscale enemy damage.
“Butbut it’s not that hard to get a party”
The point is not how hard it is to get a party, it’s that a solo experience is suddenly broken up in favor of a random party event. For comparison, imagine you’re playing, say, a Final Fantasy game, and just as you’re about to get to the final boss, a prompt pops up saying “To fight the final boss and see the epic conclusion, please get 3 friends to buy a copy of this game and use link cables or some other fumbly nonsense to connect your consoles together. Thanks for the money, sincerely, square enix.”

So I’ll stick with my explanation that the final quest is a programming bug nobody caught in time for release, and I humbly request that it be patched as soon as possible.