We thought the rider fell off or something and it was going to crash. Then it turned and kept mowing. Park Roomba!
Another picture:
Depends on how much maintenance it requires. And someone is going to need to be paid to deploy it and watch it to ensure that nobody fucks with it and that it doesn’t eat some park sunbather or something. And to make sure the grounds are clear of debris. Etc.
Don’t think you can count on just removing a salary here.