I understand the "not my thing" point of view.
I don't understand the "can't get through much more than an encounter or two" views though.
In 5e? In 5e you can get through a huge amount in 2 hours. Heck, WOTC livestreamed their games - how much of the Slavers series did they get through in 2 hours? It sure seemed like it was a lot.
I am wondering if people are answering based on their experience with 3e and/or 4e and extrapolating that to 5e?
They ran 4 2h sessions and didn't even complete the main story they were going for. On each individual session they got a bit done, did a fight or a few but over all there wasn't much accomplished week to week.
Is it enough time to clear a floor of a dungeon? Yes. A full dungeon? Possibly. It is enough (for me) to get anything significant done? No.
Yes random fights were finished in the 2 hours. But if this is a single, one-off, game unrelated to anything else - then NO I don't think they got enough accomplished. That is my opinion based on the live streams.
I'll say it again; it doesn't matter how fast the combat is - I don't feel 2hours is enough time to get invested and wrap up a singular game. If it is a 2 hour session of a longer game - then I think that is rather short, as I prefer 3+ hours at a time - then I'm in. But as a single session out of context I don't think I would be satisfied.
And given that a one-off unrelated to a recurring game was the condition first given I feel confident in saying "No" still.
Now, Mistwell if you have a different set of conditions that you would like me to answer I'll try my best, but my answer isn't based on my 3e (I have no 4e to speak of) experiences, everything I answered here is based on the livestreams which were fully 5e.
You can certainly get some things done in 2 hours, I just feel you can't get enough done for it to feel complete IME/IMHO. Your mileage may vary.