;o
Egg lay is highly understood by many yoshi mains because they simply do not use it enough or correctly. Talking to the top yoshi mains (bwett, green ace, stocky), they all agree that it is definitely one of his best moves. Talk to your typical yoshi main and they think it isn't that good and that Fair is really good.
I'm not necessarily being mean with this statement right here because it is a very common pattern. Impressionable yoshi mains see say scatty's combo video and think Fair is one of the greatest moves yoshi has: it is not (not to dis on your combo video scatty, it is awzum). Fair is generally a move that will only work when your opponent has made a big mistake. If it had the lagless ending and disjoint of say peach's Fair, then by all means spam the **** out of that move, it would be your best spacing tool. However it does not and has really been nerfed from melee (where it was sex). Now it is simply an attack that just exists and doesn't really have that much of a use (comparable to samus' Nair for example, it has some uses but it really is kind of a waste of space).
The false attitude about up tilt was started with Pride by saying it was his worst move, so I blame him for that ;o. It really is yoshi's best tilt but I don't need to list the reasons because that's what the summaries are for =]
Dair is better than Fair, end of story. It actually comboes (Fair can combo but I don't see anyone consistently nailing good players with it), adds enormous shield pressure, and works perfectly as one of yoshi's tools from the ledge. The fact that it can combo into Nair, Bair, or Uair only makes it that more delicious. It isn't a good move, it is situational but people tend to underrate it because so many yoshi mains do the scrubbiest thing and directly approach with it (if you fullhop it then that's fine, the extra mixup helps and no end lag is nice).
Downsmash's reasons for use were listed in the summaries, people are turned off by it because of it's nerf.
So basically Lil B just listed Fair as being better than attacks that really aren't completely understood by many aside from the top yoshi mains. Note that a lot of top yoshi mains understand this move, the misunderstanding is just a pattern I see in average yoshi mains.