I used to be a waitress but my boss at the restaurant was a grade-A beeyatch.
She wore really hideously ugly trousers (ghastly skinny red tartan ones) , but gave me hell unless I was wearing a skirt - even though they have no pockets.
So it was impossible to put tips into a pocket and they would be kept in a jar instead.
But, then she would just steal all of the tips to keep for herself.
She did this even though she only payed £3.26 an hour (really more like £2.50 an hour because she would get you to do overtime with no warning then weasel out of paying for it) , and even though it was like pulling teeth to try and get paid for work which you had already done for her.
We were the only two people who worked there and she was insufferable in so many other ways too (and kept trying to con the customers by lying and telling me to lie to them - even though I never did).
She always had the obnoxious "Mark and Lard" show on the radio in the kitchen - blaring really loudly, so she couldn't hear a thing which anybody said out in the restaurant part of the room.
So whenever customers looked pleased with my service, I would explain to them that my boss just kept all of the tips for herself... and would request that if they liked my service then please would they NOT tip me because frankly I'd rather they did that than tip her for my good service. They would often look quite shocked, but by her attitude... they would make it clear that it was good that I'd drawn that to their attention, while popping their purses away.
Sometimes I wouldn't catch them in time and a tip would be left.
Eventually I thought of taking some of the pound coins and storing them in my shoes.... but it was really uncomfortable and I felt like a thief just taking some of my own tips in that manner.... so I felt horribly guilty about it.
The woman was very abusive towards me - verbally, intellectually, professionally.
Long before I thought I was autistic she decided that I was, then used that as her excuse to call me a moron, a special case, ret*d etc.... Well, needless to say I was the most inept employee in the universe (to her, not the customers) once she started that nonsense up.
The reason I say all of this is because goodness knows what goes on behind the closed doors of other restaurants.
If the waiter was having to put up with his boss stealing all of his tips and giving him barely any pay even after a struggle to get it , then it's unlikely that he would care at all whether you tip him or not... and might even secretly be trying to put customers off from leaving any tips at all.