Bosh is the third option on a repeat-champion team with a generational player and...well, an overrated old guy. The media exposure from that alone is superstar-level, even if a lot of it comes from "he looks like a velociraptor" memes.
"Good player" is probably underrating him, too. I've interviewed around regarding advanced-stats positions with the NBA and the consensus among people I've talked to is that Bosh (who comes up a lot because he's sort of the "smart NBA player" poster child, non-Battier division) would put up titanic numbers on almost any other team. Watch Al Jefferson in Charlotte this year--Bosh doesn't have the post game Big Al does (but is still probably top-10 in the league), but can shoot from mid-range, make plays for others, and play defense both on the man and in help situations.
Bosh did put up Titanic numbers as a number one option on the Raptors, and is a fixture on Team USA. "Superstar" may be a slight overstatement, but given the overapplication of that term to "any famous athlete," I don't think it's worth quibbling with.
"Good player" is probably underrating him, too. I've interviewed around regarding advanced-stats positions with the NBA and the consensus among people I've talked to is that Bosh (who comes up a lot because he's sort of the "smart NBA player" poster child, non-Battier division) would put up titanic numbers on almost any other team. Watch Al Jefferson in Charlotte this year--Bosh doesn't have the post game Big Al does (but is still probably top-10 in the league), but can shoot from mid-range, make plays for others, and play defense both on the man and in help situations.