I don't see table top RPGs as particularly immersive either.
I mean, half of the time I'd just be drinking and bullshiting with friends, rolling dice. No one was ever getting really immersed in the story in the same way you do when reading a book or playing a game alone.
Not to say that's bad or anything. It has it's place too.
Well the assumption that people will "bullshit" while playing with you doesn't really hold ground. With friends I could see it happening, especially if you use VOIP, but with random players, people just play the game.
In ME3, while there was an occasional troll, most games were "serious" with players seeking to accomplish the goals as quickly and efficiently as possible. I felt more immersed in the game as I felt the immediate threat of destruction via my war assets (as in the characters you play).
I don't think most people will really mess around. At most, I can just disable VOIP and pretend my partners are n00bs of the inquisition. Every organization has incompetent people after all 
But I see where you're coming from. It's a subjective way of thinking after all. I find myself capable of zoning out these external factors. The only thing that really ruins immersion for me is a gamebreaking bug.