I would like to point out that picking an assist for big damage rather than neutral game is counterproductive, because if you have the mindset of wanting to get big damage then you are finishing combos and always set the game back in neutral. You are picking an assist that is bad at neutral and forces you to play neutral. The dichotomy is neutral oriented assist vs reset oriented assists, and the strongest assists are the ones that do both like updo and hornet bomber. High damage vs neutral game is not a usefuldistinction in practice.
Edit: sigh, typing on a phone is hard.
I see where you're coming from, and you're certainly not wrong, but I'm not either & I'll tell you why inabit.
Okay so I typically don't like combo-focused assists for obvious reasons, but I am starting to a bit more these days too for some of the same reasons.
/snip
TL;DR: yes assists for neutral is good, but you must reset quickly after for damage & constant resetting invites mashing of all kinds. Think about it. You're having to reset TWICE as much. Once for the assist itself, then twice for reset of scaling. In addition, damage is typically minimal & bad for combo extension if you get in without it. It allows for easier autopilot neutral, but killing an opponent will take more "work" in the sense of a lot of hits, but less damage & more opportunity for them to weasel out.
On the flipside, combo-focused assists allow combos to EASILY reach 7k at LEAST. no bar. For some, 8k easy no bar & others 9k w/bar. Think about it...that's more than half or at least half their bar with NOTHING they can do about it. No raw tag bull, no air mash supers, no safe DHCs...nothing. They have to sit and take it. A combo with just 1 or 2 resets after no strings is game from there if you wanna reset, but you don't have to because one more combo is death for that opponent lol. See what I'm saying? Your neutral game needs to be TIGHT & for some that's a lot of work...trying to get in, but once you get ONE hit, that's half health minimum.
Soooo basically it all comes down to your play style. Are you secure in your reset game? No? Get an assist for it! Maybe you are secure...well you can bolster it MORE! Or perhaps you don't mind less tools for finishing for hits...but when you do, you tend to take away a LOT of guaranteed health? We'll bolster it more & take away MORE health! Orr...just get napalm pillar and be done with it all :)