Do many gamers watch a lot of YouTube Commentaries?

I'm curious how many people really watch and enjoy these kinds of videos

No one.

YouTube is plagued with them. Got old real fast. If it's people teaching strategies that are actually useful, then I'll say "Ok," and watch them. But most of the time is about a person's fake ass life story, or them talking about "YT drama", or bullshit rumors they claim to be real for upcoming games, or them going "So uhmmmmmmm sooo yea this is ummmm me going um 34-2 um quickscoping in uhhh Call of Duty soo yea"

Depends. Are they giving perspectives about games that you wouldn't have considered if it were just you. I'll entertain Totalbiscuit and Angry Joe or Errant Signal somewhat but only on subjects of interest.

I watch Game Grumps if that counts. I'm not really a gamer anymore though.

From time to time. Not that interested in YouTube commentaries or Let's Plays now days. Speed-runs and Live Streams are pretty cool.

I actually hate them. I rather just watch gamestop or ign reviews.