Eh... I really don't agree.
Dreams is a complex tool but it's nowhere near as complicated as learning all the things you'd have to do to build a game in Unity. Getting a decent result between animation, art, audio and logic in Dreams is far more achievable than it is on Unity. The other point is that, while you can't sell things in Dreams, being able to publish to an engaged audience of people is a major positive. It's all very well to think that you could 'at least try to sell it' after building something in Unity, but there is a gigantic gap between making a game and being in a position to publish it and an even bigger one between publishing it and making even a remotely meaningful amount of money.
If your intention is to get into the games industry, then yes, I would suggest Unity over Dreams (though I'm not sure I'd actually suggest Unity over other options...) If you want to make a game? I'd suggest Dreams over Unity.
(I'm a professional game developer with some unity experience, and I love Dreams)
Oh yeah for sure you'd still have quicker results in Dreams. It's definitely still a world of difference between it and actually making a game. And I cant deny how much work there is to learn each individual aspect of making a game from scratch (humanoid animation is a bane on my life) in comparison to the tools provided in Dreams.
But I guess to me theres a natural progression from these games, which is perhaps their greatest aspect. For me I started on lbp, then went onto modding for KSP via Blender/Unity, then sculpting etc as a hobby for pure fun and eventually converting/modifying models for VRchat, which got me to try Maya and now I kind of just experiment with both that and Unity.
So in a sense it was MM games that led me down this path anyway (I actually tried UE3 and CryEngine during the lbp days but I was out of my depth at the time) as they were a window into a field that interested me but was beyond my understanding. Eventually it gave me the confidence to take a step through the door instead, but I've never felt the need to look back through the window as much.
Dreams is amazing, but the freedom it provides does make me feel I should be looking at industry tools instead. Perhaps more so as I don't have the skills to be a part of the industry so I see each project as a step closer. Whereas in contrast if I was already well versed enough to land a job with it I might feel less like I'm burning time I could be investing into industry tools instead.