Platforming being seemingly removed from World of Light is actually a good thing. I like Subspace a lot, enough to have replayed it a few times, but the platforming did not play to the strengths of what Smash is all about. If I wanted to play a platformer in that vein, I could play 5 other Kirby games and get a similar and, in my opinion, better experience. Melee Adventure Mode has a lot less platforming than you remember, by the way.
Meanwhile, World of Light plays to the strengths of Smash. Fights with various conditions and stipulations have been with the series since Melee, and adding the Spirits concept to give each fight a flavor they've never had before elevates the variety and creativity.
Stage Builder has been and always will be an inferior time waster. The tools present in both Brawl and Smash 4 haven't been fun to mess around with, and you're not having a good time if you stick the AI on there since they almost never know what to do. 103 stages + Omega/Battlefield variants are plenty of variety and have a bonus of not being total eyesores.
Trophies have served their purpose. As a celebration of Nintendo's (and other companies') past, Spirits lets them cast a much wider net by relying on official art. As a source of information, the various wikis and Youtube are superior and up-to-date. As collectibles, again, Spirits serve a gameplay purpose that trophies never have; most of the time the trophies are looked at once and never again. As eye-candy? You got me there, and I love seeing my favorite characters rendered in glorious HD like Star Force Mega Man, but it's entirely superfluous and it's not as if the official art is ugly. On the contrary, the official art for what we've seen so far has been full of personality.
I'm going to be honest, the belly-aching for characters has been getting on my nerves the past couple of months. Before E3, it was the cut veterans + Ridley, and K. Rool, but especially the cut veterans. By the August Direct, every one of them had been confirmed + a number of Echoes as bonuses. Despite the initial Direct making it clear that the decision to bring in everyone from the past games meant much fewer brand new characters, I've still seen many people conflating their disappointment that the Grinch hoax was fake with the game lacking content.
To be clear, there's nothing wrong with wanting certain characters to be playable at some point, but there's also such a thing as keeping your expectations in check. It's entirely possible that some of these characters will indeed show up as DLC down the line. But there's no way I'd delay the game for any of this.