He isn't lying at all.
If Giannis leaves even after all these moves the Bucks will be bad for a long time. They have mortgaged their future big time.
The other big thing is Giannis has to get better as a player. He has got to be able to hit at least mid 70's from the line and either get a go to post move or get a consistent mid range jumper. The last two playoffs the teams that knocked them out of the playoffs neutralized his offense. He didn't even average mid 20's in points per game against Toronto and Miami (he did get hurt, but still) the last two seasons. The teams just slowed them from running and kept Giannis from driving into the paint.
He definitely isn't getting as much flack as he should for those Bucks teams underachieving in the playoffs. I mean the team does need more but usually the great players raise their play in the playoffs but the last two MVP seasons in the playoff series losses he hasn't played well