It's very very clear they're eating their own dog food, in a product space built on tech that didn't really exist publicly 5 years ago, to the success of billions, that people increasingly depend on. Maybe I'm an optimist, but I can't fathom the intense negativity or perspective of failure here.

Don't use it. Maybe wait a few more years. If it's not valuable/useful, then not using it, while everything matures, will not be a problem.