Probably because broad adoption would help making it a real option to use in the near future?
So sure, Samsung would bundle it with their usual crap, but if it helps making the engine more mature, great, but I also don't see why they would in the first place.
In fairness, while there was definitely Mozilla mismanagement, there was also a massive monopolistic marketing/bundling campaign by Chrome. Google search and other properties pushed Chrome, Google paid application publishers to bundle Chrome the way they bundled adware, and so on.
Their performance is not great comoared to the competition and their market share is at 3.7% and falling. The only thing that keeps me there, is ublock origin. The moment ladybird or a a servo base browser becomes an option I switch.
And if FF also starts to restrict UO, I just go to chrome then. I assume many think like me.
So sure, Samsung would bundle it with their usual crap, but if it helps making the engine more mature, great, but I also don't see why they would in the first place.