TNG was great, and the best episodes are incredible, but most episodes were fairly mediocre. I feel SNW's average is higher, and it's probably in part for having LESS than half the number of episodes per season.

I think they'd be fine with 12, maybe even 14, but beyond that I don't they could keep it as great as it's been.

TNG is my favorite for now because it finished well, in spite of the notoriously bad episodes that were in each season. SNW hasn't finished yet and could screw things up, so I can't say it's my favorite yet. But when comparing the two seasons of SNW to any two random seasons of TNG, SNW wins. Episode count and quality aren't necessarily linked, true, but my point is that there's a higher chance of introducing poor episodes when the season is longer. A longer season could produce 20 great episodes instead of 10, but I have yet to see a show where this happens.

Up until Trek started streaming, the longer seasons were all we had, so comparing NG to all the other shows before streaming, it's my favorite. Mainly comes down to the characters for me, as I think the storytelling in the network shows after TNG were just as strong as seasons 3-7 of TNG. And even though Disco and Picard had shorter seasons, they suffered under the weight of having to fill a predetermined episode count with a serialized show, so yes, episode count and quality aren't necessarily linked. But an episodic show with a shorter season means the show runners can be picky with the episodes they want to film, much as a chef can be picky with what dishes they want to present.