I'd say yes and no. It's true that there's not a huge appetite in the league right now for 6'0 two guards that leave you exposed to all sorts of mismatches on the other end. He does not seem particularly well-built physically for the gauntlet that is playoff basketball, and that's probably the most damning thing you can say about him, in addition to the fact that he hasn't been efficient enough - especially in the postseason - to warrant shooting at such a high volume.
But he's also clearly not the same player physically that he was in Charlotte, which makes him tough to judge. His production over his final few seasons there can't be marginalized, especially given how much better he was defensively compared to other smallish guards like Isaiah Thomas, Lou Williams, Jason Terry, etc. All the data pointed towards him being a legitimately really good player that carried those Charlotte teams.
Ultimately he found himself in that no man's land of being overqualified to lead bad teams (hence Charlotte picking in the late lottery every year) but maybe slightly underqualified to put a good team like the Celtics over the top. There just aren't a lot of guys like that.