Some may have noticed that Falcos have been recently doing better than before in competitive play. You may want to take a look at the tournaments results section to see that.
It is also noticeable that some players got very decent results with characters that were I think a bit unexpected at this level (Collision 2019 namely). In my very humble opinion, this highlights the fact that there are a lot of viable characters, including at high level. Falco may not be as high as other spacies in tier lists, for what that means, but I guess he is still capable to win at the highest level in the right hands, and the same may be true for many other characters.
That said, as a very low level but enthusiast player, I think Wolf has a learning curve that is much faster than Falco's. If the same goes for players much better than me, that may contribute (among other factors) to Wolf high popularity. Maybe things will change a little bit in the future, especially if Wolf gets a few nerfs.