Well, of course, I was only talking about my own experiences. Yak and Yeti has never been crowded when I went, but of course, that's just me, one person, and I guess I shouldn't have assumed that was indicative of how it always is. I also tend to go to Disney during weeks that were really good for crowd levels, as in I never go when the kids are off from school or during a holiday week.
I know there are those who are constantly saying Disney is always crowded but that hasn't been my experience when I've gone the last 3 years on my 10+day trips which were in Jan/Feb '16, May '17, and Nov/Dec '18. It was just the normal crowds, nothing excessive or crazy and while I did have advance dining reservations, many of the places I went, especially second tier resort eateries or some of the World Showcase restaurants always had plenty of open seating while I ate. Again, just my experience. For what it's worth. Some restaurants were busy but they were the ones that always are, like California Grill or Coral Reef, ect.
And on my last several trips, I did use the Disney App quite a few times to change or make same day reservations and almost never had a problem getting what I wanted. I mean, I would basically ALWAYS advise to use the advance dining system if for nothing else, for it's efficiency and ease of the entire experience, I was only pointing out that sometimes you do that and then walk into a half empty or even more restaurant (as happened to me at Tiffins last year). It was merely an observation I have noticed from time to time at some of the many eateries I partake in (I do 3 sit-downs a day on my trips) But it is, of course not something you can count on.
So, I didn't mean to imply that you shouldn't make a dining reservation because you most certainly always should at Disney even at places almost always hardly full because you never know.