I have three robots in three pools. I've been using them for about 15 years and I love them.
They are not for everyone, but "most" of the people that don't like them have never actually used them. I few have found that they cost more than they wanted to spend, but even they will admit they do a great job of cleaning your pool.
I also have saltwater pools that have salt cells. I consider the cells to be consumables as I know they will only last about 5 to 7 years before they need to be replaced. I consider robots to be consumables also. My last robot lasted 7 years. Even at a $1,000 each, if they last for 5 years that is $200 bucks a year. I see that as a great investment in my pool maintenance.
I find it funny what some people consider valve compared to others.. My daughter would rather cut off a leg as not have a new iPhone. I find that a total waste of money. She does not. Whether robots are a waste of money is in the eye of the individual pool owner.
Thanks,
Jim R.