Danny had a long plan in place pretty much since 2012. He had himself in position to legitimately make big moves multiple times. Was a viable contender at getting Durant before he signed with the Warriors, signed a couple bigger FA's at the time (Horford, Hayward, Kemba) we can talk about in hindsight those moves not being great, but the reality is the Celtics didn't have stellar Free Agent signings prior to that. He missed quite a few later draft picks, but nailed his two major draft picks (Tatum and Brown)
I think Ainge did a decent job post 2008... Obviously they fell short of the ultimate goal, but the team had a 3 year window where it was legitimately in the mix to win it. I think the issue with Ainge was he backed himself into a corner near the end where his options were limited. He had hit a couple homeruns with Tatum and Brown, and was banking on hitting one more homerun with a functional Kyrie Irving, and somehow luring Anthony Davis to the team. That homerun never came.
With that said, I am extremely pleased that a change was made. Brad has no connection to these moves / long term plans that Danny made. Brad has the flexibility to chase other potential routes to success that Danny couldn't really do without having to explain what he had been doing the past eight seasons. I don't know exactly what Brad is doing, but it does somewhat feel better knowing that moves are being made. Brad seems extremely active to start, which is just a complete change from how Danny operated the past few seasons.
I know change isn't automatically going to fix problems, but the fact that things are changing makes me feel better.