Probably. I dont know if I have enough info about the process to have an informed opinion on this tho.
It just seems to me that with mocap you can "fix" and edit whatever you want of the actual acting to make it work, whereas in traditional acting you dont get to fix that much in post production, thats why theres a ton of movies with a ton of takes and a ton of reshoots and whatnot.

There us definite things in Mo cap editing that probably weren't there indeed, that's what got me wondering on this. For example Eve's body shape, she has a severe spinal deformity but manages to have perfect posture which isn't happening in real life but is that really acting. Perhaps an anime wink or an exaggerated smile in a game like Rebirth or Death Stranding 2 could put a stopper in the idea that it is true acting. Someone put it really well above though, you can't say Henry Cavil wasn't acting cause they removed his mustache with CGI and actors scenes have been edited since the beginning of film where as to games they have to get the acting down and it costs so much to animate it's not simply a case of having a dozen takes for any scene to stitch together. I'd reckon it's true acting, definetly now that actors on Marvel films are doing exactly the same thing for live action with a bit of a more complicated set. 

Kind of?

Watch Troy and Ashley and tell me it's not acting. Also, voiceover work without motion capture and such is acting too. 

Even then...

Absolutely it is.

The work of actors like Andy Serkis in bringing to life characters like Gollum in LOTR, Caesar in the new Planet of the Apes films, or Monkey in Enslaved: Odyssey to the West was a huge part of why those characters felt so believable.

Body language is a crucial part of acting.