But if consistency is your thing, you could retcon the whole thing by making the busboy an in-restaurant hologram. It would be like the emergency hologram doctor, except the hologram busboy would just be an artistic feature. In the Star Trek economy, you are paid in public appreciation for your talents. The richest person in the Federation is the one who has the most fans and followers.
So without scarcity, a lot of people would give away their holographic models and software, for the prestige of "holographic restaurant busboy reaches one million downloads!" It wouldn't really be any more complicated than visiting Nexusmods to get a modded Fallout or Skyrim NPC companion with full dialogue and bonus companion quest.
If the busboy is a character that also interacts outside the restaurant, that was just the guy who scanned his own likeness and programmed a facsimile of his own personality to make the busboy hologram. His real job isn't bussing tables, it's making it look like restaurant tables are being bussed instead of serviced remotely by transporter/replicator/hologram technology.
Does that make you feel better about the guy who does menial labor in a scarcity-free economy?
Also, at one point, there's mention of "teleporter credits" as an explanation of why going off to academy caused homesickness -- couldn't teleport on demand. Even in the Culture, citizens had to show their capability quite a bit to design a part of an orbital. They couldn't even get their own ships on demand.
Trademark enforcement would probably be one of the things kept in a post scarcity society, if there was any system of reputation left! Being an X(TM) athlete comes with prestige so you wouldn't want someone else to be able to endow that prestige at will.
The Starfleet holodecks are just scarce because the operating code and hardware has to be formally validated and certified as safe for use in Starfleet vessels and installations. It's like how a GPS device is really cheap, until you want one permanently installed in an aircraft cockpit. Even then, malicious code (Moriarty, if I recall correctly) could break out of the holodeck sandbox and compromise connected systems.
* Removal of energy scarcity - dilitium is mined off planets, by robots and provides cheap limitless energy
* Replicators - Controlling the atom to the point where we can make exact duplicates. If everyone can replicate a Rembrandt, the original no longer has its insane value. There's no wait to authenticate if something is "real" or "original" Some people prefer "real" food, even realizing the difference is pretty much all in their heads. All basic things can be copied and only the very complex can't be duplicated (like Lt Commander Data's brain).
So in such a universe, an athlete gets everything a regular earth citizen gets, and visa-versa. It doesn't matter if you're in Star Fleet or choose to bus tables in a restaurant, you get the same type of living accommodation, and you can live or work anywhere thanks to transporters and limitless energy. People choose the jobs they want. Star Fleet isn't a military operation and you can resign at any time. In this world, a lot of useless jobs would go away .. Olympic committee trademark enforces for example.
The whole thing breaks down terrible in some episodes. In DS9, Sisko's dad owns a restaurant with a bus boy. Someone chooses to be that bus boy .. for no money. Maybe if the writers used a robot bus boy?