It is all about the ROI. A lawn cut from a professional can cost anywhere from $25-$100 on an average (per cut). So with a $1000 lawn mower, you will get the return back in 10-40 cuts at most. That is less than 1-2 seasons. Sure, there will be some maintenance cost over the years but if you look at a 5-10 year period, it is totally worth doing your own. Even with the $1000 price tag. Of course, you cannot count the labor time.

There is more to yard work than mowing the lawn unfortunately. Trimming. Fertilizing Etc etc

If I can get a robot replace a gardener who I pay $170/mo for 2 visits per month, i probably would. But I suspect that would kill lawn