My problem with Flatpak is how huge are the downloads, especially when on a metered connection.
Last month I installed Kdenlive, and the size of the downloaded files was around 3 gb, to which the app itself contributed around 40 mb. (I use Ubuntu.)
A week later, I wanted to install another app (I forgot which one), but again, it was 3 gb download for 30ish mb app.
And then this week I ran `Flatpak update`, and it needed yet another 3 gb to download just because there was a new Kdenlive version (again, around 40 mb)!
How on earth does it make sense to have to download 10 gb worth of data just for apps that only total 100 mb?