I'm not a Howard fan, but he does offer rebounding and rim protection and a physical presence underneath. His decline in scoring can be attributed almost directly to taking fewer shots per game. He shoots at basically 60%.
2013-14: 11.3 FGA, 9.0 FTA,18.3 PPG
2014-15: 10.3 FGA, 6.6 FTA, 15.8 PPG
2015-16: 8.5 FGA, 6.7 FTA, 13.7 PPG
If he took 10 FGA a game, that would have ranked him tied for fourth on the team this past season, behind Thomas (16.9), Bradley (13.4), and Crowder (11.1), and tied with Sullinger (10.0). Assuming Sully is gone, Howard basically replaces him. And he's much better than Sullinger is. Yes I know they play different positions. I'm just talking mostly about touches and FGA and production.
And if Howard gets 10 FGA a game, and, say, 7 FTA a game, we're talking about a 15-16 point-per-game scorer on the interior. They haven't had anything like that since KG averaged 15.8 PPG in 2011-12.
Geez, am I talking myself into wanting Dwight Howard on the Celtics???