Back then toys were barely painted and stickers provided necessary details. They look so plain and uninteresting without the stickers. Even the most brickiest of a toy was made more exciting to look at because of the stickers. I think Cyberverse toys also require stickers as without them they look plain and uninteresting to me.
Any toy that's lacking in details and colours to break the parts/sections will look bad and/or worse for it, that's just a given. But between stickers or paint, I'll take paint 10,000 over.. if anything I'd rather not have stickers and plain so to be able to paint such a toy if they manufacturer was too cheap to do it. Stickers that "replaces" details are flat are almost worst to me, I'd rather a flat surface over a sticker that mimics details in a 2 dimensional paper trying to imitate 3d details. All stickers eventually peel off, warp, scratch, fade, etc. and ends up making the figure/toy look terrible in time, some gum up the figure, some actually damages the surface of the plastic.. "Team paint" for me all the way.
They do look more show accurate without stickers, though, since most of the details stickers provided were omitted in the cartoon. All my old G1 figures have their stickers applied and yes, they look better. However, every reissue I bought, be it regular or e-hobby, is still without stickers. I know they look better with, but I also like them without.
Stickers are a must on G1 toys, unless we're talking one of the reissues which replaced the stickers with tampos. ANd even then I think they only replaced the factory stickers, not the full set.
It's entirely dependent on one's preferences. In the 80s, I applied them all because why wouldn't you #UseAllTheStickers? On the reissues (which I didn't purchase after the Dreamwave boxes ended other than the first Encore Predaking), I only applied the stickers where they matched show accuracy as long as there wasn't any collision/clash point which would result in wear/scraping/peeling. Most of the stickers at that point and beyond for me were complete overkill and not something that I wanted to worry about.