They are identical in that they are below the championship standard you continuously allude to. Origi has been shit for Liverpool in the long run bar a few anomalous performances, which do not justify having him around as long as the club did. That is if they were to religiously adhere to the standard you purport the club should hold itself to when contending. They should have sold him a long time ago and bought a guy like Jota in way earlier, but they don't, making 'standard' argument being moot in these cases as top sides don't care about ruthless application of it as much as some fans do. Same at Bayern.
Relatively poor players absolutely can be net benefits to teams like current Barcelona, because they know they have no right to an ego. The minimum for him is to put the work in and when guys like Braithwaite put the work in, the rest of the better players you have, who do not consistently apply themselves or get frustrated at their teammates/their manager for failing to put them in position to succeed, will look worse for it and showcase lack of flexibility, resilience and leadership. As they can't even do what that guy who's getting consistently fingerpointed at does on a regular basis, leading by example far more than they do. Thousands of examples of the same mechanism working in a variety of settings in sport and life.
Braithwaite will continue to be at Barcelona as the club will likely have no money to buy a different player capable of playing CF better than him, and he's not a priority to replace - starting forward is. Unless a better forward surfaces from La Masia, which is not looking likely.
Not because there will be no buyers (there would be enough, for less money than Barto paid).
He will stay and continue to be a backup for bottom La Liga (as he should be).