tipping doesn’t improve content quality nor materially contribute to growing this place

Yes and no. 
Quality is subjective and people who want to show their support to what they consider quality have an easy way to do so.
Thats not to say there won't be bad actors or coordinated farming attempts, but it feels like we're in the next era where services like @noiceapp are accounting for this in ways that previous tipping mechanisms didn't.

I like running, poker and oysters | Founder, Social Forensics | Berkeley & UPenn | Learning to listen