Sorry, I quoted what was in the reply. I understood it’s not your reply but a quote of someone else’s. Sorry for the confusion.
Fedora Flatpaks are there because they are the only ones that can be installed by default for licensing, etc. reasons (see the latest discussion on the topic in Flathub and the bundled software policy - #3 by toMeloos). Moreover, having them and the runtime installed does not really increase disk usage much as most content is de-duplicated already thanks to ostree.