Earlier quoted context omitted.
You're removing the middleman (Play or F-Droid) so I don't see how.
Usually the middleman validates what the stuff does, before we do it ourselves, yes even though malicious apps get through the cracks, still makes a difference.
In these cases, the middlemen like Google are the hostile party. Essentially the threat actor. It is natural: big tech is big tech, because they are very good at limiting user choice.
For these applications, Obtainium is brilliant.
It also shows that the store model that everyone is working to enshrine in digital policy is not the necessity that Big Tech would have everyone believe.