I think it’s more likely that Sonic is just a very large children’s franchise and the dude is fine acting in them for that reason. I think what I’ve gotten from his stance on “retirement” is just that he’s tired of doing it for the money and experiencing the awfulness of Hollywood in general. But if it were me, yeah I’d come back for a beloved children’s franchise.

A definite possibility. Or perhaps he discovered the being retired isn't as much fun or relaxing as he thought.

Oddly enough, there isn't maybe as much fun in fishing or traveling or pursuing a hobby(s) every day as you might think. It can be hard to understand for those of us who still need to get up and "be somebody" everyday that not having a reason to do so can lead to mental degradation and depression.