Who will prepare your food, deilver your pizzas, keep office buildings clean? We will always need people to fill these jobs.
We always will have enough people to fill these jobs.
If the wages go down to a point where they actually discourage people from working these jobs, it will then become hard enough to fill these positions so employers will tend towards raising wages to the point where people would be willing to do this work again.
If someone then invents a pizza-delivery-bot/janitor-bot/cook-bot/etc, and if the robot is cheaper than hiring a human, and it does the job exactly as well as a human, then the wages will settle down to the point at which it costs about the same to hire a human as it does to buy/maintain a robot that will do the job.
If people refuse to do the job for that wage, then the robots will just take over the entire job category, and we won't need people to do these jobs at all.
Again:
How much you get paid depends mostly on two factors in combination:
#1. How much value do you add to the end product your organization is trying to produce?
#2. How hard is it for your employer to replace you with someone or something that can do your job equally as well?
If your job doesn't score well on #2, no matter how valuable the work you are doing, you are going to get paid crap.
If you don't want to be paid crap, then you should try to choose a career where #1 is high
AND #2 is high, through methods like:
- education (getting a degree that is hard to get but which is needed to fill a job, tends to make you harder to replace)
- skills (having a skill through practice, genetics, apprenticeship, going trade school, sports ability, etc)
- legal restrictions (having a medical license, or a professional engineering license, licenses that are hard to get, owning a patent, etc)
- labor unions (using collective bargaining and strikes to make it hard for an employer to replace you)
- fame (if you are famous, especially for your skill, you tend to be very hard to replace -- think about Jennifer Lawrence, or Johnny Depp, or Tiger Woods)
(This is clearly not an exhaustive list.)
But remember, if the method is easy, then a lot of people will use it, which means it's value declines for everyone.
For example, if getting a certain degree or credential was easy, then everyone would have one, and then you couldn't use it to enhance your #2.