This is why it's so important that Tapas survives and thrives. This place is so much better for creators in terms of scheduling, little quality-of-life features, audience interaction and so-on. Not to mention, the forums here are amazing. Basically everything except audience size and exposure, really. As Tapas continues to grow, the competition pressure will force WEBTOON to adopt some of those features, however slowly.
That said, it'd certainly be nice to see that process speed up! WEBTOON is a Korean company, so I'm not sure how effective a bunch of western CANVAS creators could actually be at lobbying for changes to things like the rating system. That said, it doesn't mean trying is meaninless.
There are a couple of subreddits dedicated to WEBTOON, and one for CANVAS specifically. That'd be the place to try organising, for instance, an email campaign regarding features important to creators. r/webtoons and r/webtooncanvas are the two most populated ones. There's also a Line Webtoon discord, though it's not terribly active.
I don't have the time to spearhead something like this, though I'd certainly be on board to support it as much as I could, should somebody else take the lead.