Oh, another point: while humans today can make a new human in 9 months, but building a robot takes longer, once that robot is finished, it’s ready to use. With a human, you need to factor in about 20 years of feeding, clothing and educating it.
In the future, we probably won’t need a lot of mexican housemaids, because the house will be more or less self-cleaning, maybe with dumb robots like the roomba, and the fridge that orders food per the internet, windows and walls coated with paint on Lotos effect so dirt washes off with rain, remote-controlled via cell phone window shutters or ovens etc. All available today or soon.
Instead, we will need more and more highly trained and educated intelligent humans. We already see this in todays society - the jobs that untrained, unskilled high-school dropouts and illiterate immigrants could work in the 50s have disappeared or changed to a higher skill level by about 80%. In the 50s, a dockyard worker was told “go from here to there, empyting this pallet”, even if he couldn’t read or speak the language. Today, the same job requires reading and basic computer knowledge to scan in barcodes into the computer managing the whole store and assigning the work orders. For the 10-20% of barely qualified people, high school dropouts etc it’s more and more difficult each year to find a job they can do, and there will always be a bottom layer of people who can’t be trained to higher skill level.
With a robot, once you have mastered AI or advanced enough programming, instead of training a human 3 or more years for a field, you hook the robot up to the database and download the programming. Need a nurse today, a pilot tommorrow? Just switch programs. And if they are built similar to humans, instead of embedded into the ship, they can move around to different areas.
Also, you can improve a robot body with regards to radiation, toxic gases and other substances, cold, heat etc. True, we have some specialised robots today for crawling through small pipes, or clearing explosives etc.
There would still be many instances where a danger to a human might exist, and a robot would be easier to repair (I’,m assuming it’s made from metal, not grown in a vat like a clone) than a human.