Just to add to that: here are last season's average attempted passes per 90 stats (Premier League only).
Fred: 66.3
McTominay: 53.6
Gundogan: 75.9
That 53.6 per 90 is VERY low for a central midfielder playing for a top club. It's hard to overstate how low, even allowing for our quite different and more... direct style of play. Jordan Henderson is at 95.9! Jorginho is at 78, Kovacic is at 86. I didn't check everyone at Liverpool, City, and Chelsea but so far only Naby Keita has been comparable to McTom, with his 60 attempted passes per 90.
His progressive passes per 90 metrics are similarly underwhelming (4.39 per 90 minutes) and again, he's quite comfortably beaten there not just by most of our rivals' midfielders but by Fred (5.6), too. Kante is comparable to McTom on this one but well, he blows him out of the water on defensive actions. More about that next:
McTominay's passing stats actually suggest that he's some kind of defensive destroyer - except, well, he's comfortably beaten by Fred in defensive actions, too. Except blocks. They were equal on that. But tackles, pressures, defending against dribbles - Fred simply does more. The one thing where McTominay is comfortably better is, well, aerial stats. But then it would be hilarious if he wasn't.
Basically, McTominay's stats - oh yeah, he's also languishing behind most midfielders in touches per 90 - pretty much confirm what the eye test says: he doesn't do enough to influence games, he lets games pass him by a bit too much for a central midfielder. And of course he quite obviously isn't a better passer than Fred.