I watched PlagueOfGripes's video on Gohan, and a lot of it applies to Tails too.
Mainly in how because they're such "blank slates", they're an easy target for self-insertion, projection, and "wish fulfillment", in contrast to Goku/Sonic who can't be self-inserted as or projected onto because they, for better or worse, have very distinct personalities that you find either endearing or not.
