Xbox Series X alone? Maybe not. (Also, "Xbox Series", such a terrible title for a game console, that couldn't help...)
But Xbox Series S is key IMO. It's cheaper, it's plenty powerful (just at a lower resolution,) it's not the size of an air conditioner (or, in the PS5's case, a very big air conditioner,) it's easily expandable, it's simple to use and to connect up with friends, it plays pretty much all the Xbox games you own... and you can get Call of Duty for it, which is all that really matters to a lot of kids is that their favorite game is on the box. And then, if you want to brag to your friends that you're elite and they're poor, you can get Xbox Series X and feel special for having the best Xbox that they made.
Xbox Game Studios has frustratingly let down its audience with massive exclusives which build brand loyalty and rewards gamers for their purchase with experiences they couldn't get anywhere else (although Sony has struggled on that same vanguard too,) but Xbox itself is as solid a buy as ever. Game Pass sweetens the deal, but if you're buying an Xbox for Apex Legends and Minecraft and Overwatch and Rocket League and stuff like that, your wallet isn't that much different.
So it kind of depends IMO what we call "competitive". They're not beating PlayStation even with Game Pass, so without it, surely it would have been worse. But devastatingly worse? From a gamer's perspective (it'd clearly be worse from a MS stockholders' perspective,) if there were no Subscription Wars and this gen was the same as every other gen, I'm not sure how lopsided it really would have been.