It's better to pick based on specific titles and reviews rather than dismissing everything outright. Netflix does have a pattern: they often take an interesting idea but execute it without proper funding or with a rushed script. But when they actually invest properly - it turns out genuinely watchable. It makes sense to look for projects with experienced directors or studios that have already made something successful there.
Wasting time on a boring cartoon just because it's on a popular platform - no, you shouldn't do that. But ignoring everything they release there is also an overreaction. The real problem is that Netflix releases a huge amount of content (statistically around 20-30 projects a month), so the median quality is really just average. But in that pile, you occasionally find stuff that's actually worth watching.
Tip: before watching, check the synopsis + at least a couple of reviews on IMDb or sites like KinoPoysk. Usually a good cartoon is immediately obvious from the ratings and comments. Rewatching old cartoons is nice, of course, but it'd be weird to completely avoid new stuff just because of the statistics.