Luka is very much comparable to Harden, and people are starting to come around to seeing this. Harden was a very good player in his prime. An MVP level player. First team all NBA level. But because of his style of play, he did not experience the level of team success that other top players do. All this is also true of Luka.
The only difference is that this playoff run for Luka was a spot light for his short comings. I am not surprised, I have been noting this about Luka all along. Many here also see it, but for the more causal national fans, this finals run has changed their impression of Luka. The level of coverage means the media is talking about it more.
I think the biggest issue with Luka is conditioning. He plays decent defense in the 1st quarter (when he isn't pacing himself), but he is gassed by the 4th. I don't think that his defense is about lack of ability. The other thing with Luka is the ball domination (again, like Harden). Who is going to want to play with him? He has had good players on the team but they all end up leaving. Harden never figured out how to play any other way. Will see with Luka.
Luka has had 4 playoffs runs, and has been the best player in the team. Of those 4, he bounced in first round 1 time at 20 years of age against the #2 seeded Clippers. Next year the same thing against the same team in 7 games, 4th seeded then but more than likely as a result of injuries than talent.
He's gone to the playoffs 2 more times. The result? Western conference finals (where they defeated the #1 seed and lost to the eventual champions) and now in the finals.
And in just about every series he's played in the playoffs he's excelled and performed. I get knocking on Luka for his defense, but the proof is in the pudding that he has this team winning and winning when it matters which is the playoffs... and at the very least giving you consistently great offensive performances and incredible clutch moments.
In his short career, can't fathom putting Harden in the same sentence as far as the playoff goes.
Not that I disagree with your takes on things Luka is doing wrong or need to improve on, his conditioning etc., but as far as his impact on the floor it's overselling what his defense deficiencies have meant vs what his offensive proficiency has meant.