This is pedantic, but service workers in the US are generally payed the legal minimum wage.
The distinction is that a different law exists for that category of workers, not that they aren't paid legal wages.
Other countries do make exceptions to their pay rules. For instance, younger people that are likely to be working temporarily may be excluded from benefits rules.
This is even more pedantic but no, service workers are not generally payed the legal minimum wage.
Wage theft by employers is over $20 billion a year (more than all other kinds of theft combined) and wage theft happens predominantly to those being paid minimum wage.
17% of low wage earners are subject to wage theft -- 2.4 million people just in the 10 most populous states -- and the average amount of theft is $64 a week. Which doesn't sound like a lot but is 25% of their weekly wages.
The distinction is that a different law exists for that category of workers, not that they aren't paid legal wages.
Other countries do make exceptions to their pay rules. For instance, younger people that are likely to be working temporarily may be excluded from benefits rules.