I agree with the OP, this was a great year and this team had a great run. Don't over think this. We lost Hayward and Irving but still made the ECF and lost in 7 to LeBron. No shame there; in fact, that is pretty awesome.
I understand that our young kids played poorly in game 7 but we were putting a lot of pressure on some really young players. They just couldn't handle the moment; too young, too soon. Brown and Rozier in particular played like deer in the headlights but pretty much everyone (except Tatum who was about average for what he had done in the playoffs) played below what they had been playing.
Keep in mind that Cleveland swept Toronto, a really good team that had all their horses. Swept, four straight barf games by Toronto. Cleveland had something to do with that just like Cleveland had something to do with us playing so bad in game 7. Hill, Green, Thompson, and to some degree Smith are all decent veteran players. They couldn't do much without LeBron but they all played well; they were reliable support for LeBron.