If these companies fail because their quality isn't good enough to support paid subscribers isn't that effectively the same thing as people choosing to not use their platform?

Those of us who dislike these practices already have a choice. We can simply not use the service. So why remove that choice from others who don't mind ads and are willing to use the free version?

Also, forcing a paid only model raises the barrier to entry. Most of the world lives on less than $10 a day, so a subscription would effectively limit access to relatively wealthy people by global standards.