Earlier quoted context omitted.
If flatpaks weren't in competition with packages repos they would serve no purpose. They are explicitly in competition with package repos. They exist so that app developers can get their work out to users without cooperating with downstream packagers.
Overlap in functionality does not equal competition. They exist so that app developers can get their work out to users without cooperating with downstream packagers yes, but that does not keep anyone from packaging applications using the traditional methods.
When app developers needed to work with downstream, end users won because it forced app developers to keep up with the environment to meet the requirements of repo packagers. Flatpak is directly in contest with this, trading packaging efficiency and keeping apps up-to-date for app ossification and upstream convenience.