Let's not get carried away, this Bayern side are very, very good. But they're neither as good as Heynckes' best iteration, Guardiola's Barcelona or us at our best.
They let way too many high-quality chances against them. Time and again Barca, Lyon and PSG all broke Bayern's back line. They conceded 2 across those three games but in reality could have conceded 7 or 8.
Again, I have great admiration for this team and think there's some wonderful players. I've also long been an admirer of Flick as a coach. But they're not suddenly this unstoppable juggernaut. They're well placed to build on their success but in two years time this team likely no longer has Neuer, Lewandowski, Muller, Perisic, Boateng, Thiago, Coutinho etc so there's a partial rebuild still needed.