I mean, OK, I guess?
I get he intentionally wrote it like a bad fanfic, with all of the fanbase's wishes coming true and Denji just kinda coasts through life. Kinda like he's showing you how shit CSM would be if it just followed a clichéd shonen plot. But like, my man, it's your own manga you're doing this to?
And also yeah, it seems like a dream, and Denji even alludes to that in the beginning, which I guess is also intentional so that it can be read in multiple ways. Which is fine, I'd hate for CSM of all manga to have an ending that doesn't make you want to understand it or discuss it. But it really should have been less rushed. As it is, it's more of a meta-commentary than a real chapter.
Btw. I know it says THE END, but as long as Fujimoto himself doesn't confirm it, anyone claiming this is definitely it for the manga is basically just guessing. I don't think part 3 is likely, but I also wouldn't rule it out in a few years or so.