The thing that concerns me is hitting something with nothing to keep me from falling forward.
Yeah, you don't want to run yourself over!

I never use a ROPS or belt, but I also can't really see myself hitting anything larger than the field mice or bunnies that occasionally pop up in front of the mower at the last second.
But you remind me of a funny story from a buddy who managed to park his mower over a yellowjacket nest. I'll admit I might not remember it perfectly, this was maybe 20 years ago, but somehow he managed to stop his ZTR right over the ground nest of those belligerant and aggressive German yellow jackets. When they started stinging him en masse, he tried to jump off the mower and run, but his boot lace caught on the deck lift pedal as he was jumping off the mower, and he fell on his face on the ground.
To top it off, he somehow pushed one of the control levers into reverse as he jumped out of the seat, putting one wheel of the mower into reverse, while the other was still in its "park position" cradle. So, the mower started spinning backwards, pivoting on one wheel and drigging him with it, right over the opening of the yellowjacket nest.
Long story short, he suffered many dozens (hundreds?) of stings, before a tennant of the apartment building he was mowing saw him being dragged over and over across this nest, and ran over to shut down the mower. A trip by ambulance to the hospital followed.
Yeah, this was the same guy who thought "seat safety switches are stupid"', and had disabled his.
