Rimworld and Skyrim.

Skyrim, same reason as everyone, I've finished most guilds though (yeah, not you, Companions).

Rimworld I just can't be arsed to work towards any of the endings, playing thematic colonies with mods is where it's at for me.

Probably Europa Universalis 4. I've played dozens of campaigns, and clocked in hundreds of hours (>850), and I have yet to make it more than 2/3 of the way through the campaign time. I usually have a specific win condition I'm interested in (e.g. an achievement, or cool scenario), and once I hit it, I don't bother continuing the campaign.

Other than that, I tend to bail on most RPGs around 50 hours in, so I've never finished any Elder Scrolls, Final Fantasy, etc despite starting numerous times. I feel like I bail when I get too powerful, need to grind because I'm not powerful enough, the story drags and I lose track of the main story line. I still keep starting them, but I almost never finish them.

Skyrim for the same reasons.

Satisfactory 1200+ hours, and I usually end up rethinking my setup around the time I get to Aluminum production and never stay to finish things. I much prefer the beginning and middle of the game. I'm weird, though, I do the one big base thing.

Quake I have no way knowing how many hours I played LAN Quake after work with coworkers. Started with the alpha release. Eventually I did Quake World. I've sunk a lot of hours into the single player game, too, but not nearly as many.

Magic The Gathering. From the original mtg (with Shandelaar), to manalink3, and forge. Not sure if the game can easily be 'finished' tho, but it sticks..

Does EVE online count? 1k+ hours, only dipped my toes into null sec a few times. Mostly spent in low sec blowing up expensive things.

I've been trying to beat XCom 2 for years but I always end up ragequitting when I lose three guys who miss multiple 90% shots in a row, while behind high cover.

I think most new games have a modified "perceived chance to hit" that makes an XCom 90 a 70 or something.