Something Amyss said:
If you found the first two seasons to be fine, you may be done by the end of season 3. I'm a fan of the show, but 3 seemed...meandering. I mostly liked the show, but felt 3 was weak and 7...well, it felt like a different show is the biggest non-spoiler.
I'm having trouble quantifying it beyond that without getting detailed.
Guess I'll put it this way.
On one hand, the characters themselves are quite enjoyable. However, if I had to boil down my gripes with the show, it would come down to:
-There's no real sense of scale or worldbuilding. Many shows are guilty of this as well (the whole "sci-fi writers have no sense of scale" trope), but when we have a setting where we have a multi-galaxy spanning empire, and where the characters can easily hop from one galaxy to the next (stating as much when Zarkon is tracking the Black Lion), it really makes it hard to get a grip on the setting. Like, apparently the Galra Empire spans galaxies, but one ship can pose a threat. Even with Voltron, this is really stretching things.
-The plot pacing is a bit weird. Season 1 had focus in that it was explicitly based on getting the paladins ready to fight Zarkon, and Shiro wisely states that they should start off small (which circumstance forces them to abandon). Comes season 2, they're already planning to take out Zarkon once and for all towards the end. Like, what happened to baby steps.
If season 3 is meandering I guess it doesn't solve the second problem, but if the first gets better, that could help. Like I said, I like the characters, but the lack of 'meat' in the worldbuilding is putting me off. When I think of stuff like Avatar or Dragon Prince, these are examples where we get a firm foundation for the setting in addition to interesting characters within it.