You are posting this on Hacker News. Most of the people in this community live in states where waitstaff earn more than $4/hour base, thanks to state laws. Read the room.
https://www.minimum-wage.org/tipped
Only 2 of those states have a tip credit of less than $3/hr.
You're probably implying that most HN users live in CA, OR, and WA where tipping wages are not legal.
Hopefully you're not referring to the NYC area. NYC tipping wage is $5/hr less than minimum. NY state is almost $4/hr under. NJ and MA are more than $7/hr under. DE and RI are more than $6/hr under. MD is more than $5/hr under. PA is more than $4/hr under. CT isn't too bad, though, at within $2/hr under.
Somehow I doubt you're implying most HN users live in HI, IA, or ND - the only other states with legal tipping wages within $3/hr of minimum. I also doubt you're implying most HN users live in AK, MN, MT, or NV - the only other states without legal tipping wages.
Not that it matters. Even if the overwhelming majority of HN users lived in a west coast state (maybe it used to be that way, but I'm skeptical of that now), most HN users also probably don't work as restaurant staff. A bad thing isn't less bad just because it doesn't directly affect you.
Do you have an actual point to make against anything I've said?
The only winner is the restaurant owners who get away with paying their staff less.
They earn something like $4/hr + their portion of the tip share. If the tip share is not enough to bring their wage up to minimum ($7.25/hr in most cases), the employer must pay the difference. Tip share is almost never enough to make up the difference, so they earn minimum wage regardless of whether they're part of the "tip share". The waitstaff earns less with a "tip share" because their tips get deducted from in order to pay the other employees' minimum wages.
Here's an example: say you have a restaurant with 2 waiters, 2 cooks, and 1 host. "Tip wage" is $4/hr and minimum wage is $7.25/hr. The waiters each bring in $7.50/hr in tips ($15/hr combined).
Without tip share, waiters get $11.50/hr ($4/hr wage + $7.50/hr tips) while the cooks and host get $7.25/hr.
With tip share, everyone gets $7.25/hr ($4/hr tip wage + $3/hr tips + $0.25/hr difference from the employer).
It's just a scheme to fund wages for cooks and hosts using tips from the waitstaff.