Much worse in terms of gunplay, world design and level design

Don't think "Obsidian made a good Fallout game, therefore Obsidian will inevitably make better Fallout games than Bethesda" is a very strong argument. And its the only one people have.

They would have been... different. Impossible to say whether that would mean better or worse.

I think FNV is special because it was the only one of its kind. It would be sad, I think, to see it rehashed over and over, and may have resulted in its charm being lost.

They wouldn't exist. There's a reason Obsidian sticks to the West Coast and Bethesda to the East. Obsidian likes things to play off eachother, continually evolving.

Their Fallout 3 plans (Van Buren) would have taken place in the southwest roughly between the timeframe of Fallout 2 and New Vegas.

New Vegas would be their Fallout 4.

Their next game would probably be in the Northwest or somewhere more inland as the NCR would be a bit tired at this point. I bet they'd want a new focus. New Cannan, the Khan migration, or Legion would serve as a link to the past games.

I don't know how or if they'd do an online game.

I can safely say dialogue would have been treated much better than what it was in F4. I love New Vegas, but as Sax said it’s difficult to say how a different team by the same name might have carried on. However, I thought the Outer Worlds was a decent AA game, and I thoroughly enjoyed Pillars of Eternity which has a dialogue system that blows F4 so far out of the water, it alone would be enough for me to say I would have still had faith in the different group to make a solid Fallout title. There’s a lot of old school, sometimes pen and paper like RPG bleeding through Obsidian, regardless of who is there, and I enjoy seeing that translated into gameplay. That while replaying Dragon Age Origins, one of my favorite games of all time, I was reminded of how much fun I had with Pillars, shows to me the magic was still there and was not exclusively tied to New Vegas.

As for what they would have done with 76? That’s much harder to say, since it’s unclear where genuine creative decisions end with that game and corporate mandated cash cow begins. There’s inklings of care, like bits of love and life that shine through, and then there’s bafflingly terrible sections often doubled down on. Entirely possible the sins of that game are a direct result folks a floor above any of the developers who worked on it, meaning regardless of what faces assembled the project, a shit show it would have remained. Because unless the team who developed 76 intentionally made it a terrible game, in some altruistic effort to kill the overly monetized M(ini)MO before it found its footing, it is very difficult to believe 76 was so bad without a significant amount of choices being made by businessmen, rather than the dev team. But ideal world, perfect case scenario? Maybe we would have had a multiplayer Fallout which was closer to DnD, with the game as our dungeon master... rather than this mess. Better now than it was 2 years ago, but still very limited.

I think people misunderstand Bethesda.

First, the cash grabs have deep roots. Morrowind was the last game without cash grabs. Oblivion had the infamous horse armor DLC. Then Skyrim had paid mods and the Hearthfire DLC, which, while good, was a sign of things to come. From there, we saw increasingly miniscule content packs: Fo4 Workshop DLCs, Creation Club, Atomic shop... To be continued.

By the time of Fallout 3, they were quite clearly going for a far more arcade shooter/exploration experience than rich, meaningful narratives. I don't think this is greed or lazyness. It's just a different idea of what the games should be. Skyrim showed this clearly. It's a fun game with a lot of content. Despite the following controvercies, it was not a cash grab. Clearly a lot of love went into it.

76 was the natural culmination of both trends. The story was never the goal, so they shifted attention to the exploration, combat, collecting, and even building. Multiplayer increases playtime, and thus enjoyment, without needing quest writing and voice acting. It's the same reason FPS games usually focus on multiplayer. It makes a good experience for many people.

Just as mods lend themselves naturally to Bethesda games, so do microtransactions. The whole point is really the amount of content. Both of these result in infinite streams of new additions. It's no coincidence that microtransactions came in the same generation of Bethesda games as console modding.

The only point I would contest there is combat, since the AI seems to either be confused by the prospect of multiple players, CAMPs, and sometimes just navigating the normal terrain. Some of the worst reacting enemies in any major game I can think of are in 76. Certainly it has all the bells and whistles to go off, with quest rewards, XP meters, SCORE meters, legendary weapon notifications, script notifications, and treasury notes... but that’s a little bit more lizard brain manipulation than it is the combat actually being honed or focused. Maybe that's overly knit-picky, but combat is most definitely not a positive mark I would attribute to the game.

Yeah. They're not coding geniuses, nor do they put much effort into it. Nothing has to be exceptional in a Bethesda game because it's the aggregation and scale of content that does the work.

You have enemies to give you things to do as you explore, to motivate you to find new weapons and ammo, to collect components to upgrade them...

While it's simple, it also works. Something like stealth-based combat, timeing-based combat, and other more complicated systems just wouldn't have the same wide appeal. They'd give too much of a focus to the game. There's nothing that can really go wrong or alienate people in point-and-shoot, other than maybe bullet spongeyness.

Better in most places but worse in others.