The round military chutes do not provide a lot of control, and at least in
the F-16 also deploy the survival kit as well as a fully inflated raft,
which trail below the pilot. This is a lot of weight, and there is a max
weight limit in flyers, mostly to insure the ejection seat will clear the
tail.

The chute is nowhere near as steerable as a square, so a good PLF is
necessary to avoid injury, and yes, I have seen at least one guy with a
compression fracture after an ejection. It still beats the alternatives. I
would not in any way classify it as fun.