I used to work the front desk of a Four Seasons. Twenty years ago I earned $15/hour for that job. The hostess at the restaurant there earned $12. Wait staff earned $15/hour to start and up to $25/hour for substantive tenure. Housekeepers started around $15 I believe. But those who had been there a long time (many of them 3
25+ years) were earning $20-$25. Bell services earned $12 to start. Those guys also saw wage increases with tenure. Some were making $20/hour and earning tips. Concierge earned something like $25-35/hour to start.
It was very common for guests to tip hostesses, waitstaff, and bell services. Housekeepers received tips often but not universally. Some guests would tip me or concierge depending on what we did for them and how rich the guests were. There was one man who had been a former ambassador who would bring two $100 bills to the front desk and ask for twenties. Then he’d give me two of the twenties. Every time. I still know his name. He stayed frequently.
So yeah, some “tipped” employees earn well. But the unexpected gratuity was always a nice bonus and recognition for outstanding service.