You do understand the difference, right? One is you going out and doing something on your own. The other is a planned event sponsored by a city. They are OBLIGATED to provide support. If not, why shut down roads? Why have water stations? Should be a free for all, right?
All events have support, some less than others, but when you do things you take risks.
Every runner knows the risks.
Your race form lets you know this is a risky event and you sign it or not!
You can ask what support is available and decide to participate or not that's another option!
Noone is forcing people to enter these events.
I always asked what support is out there when I do an organized bike race. Sometimes its one EMT team sometimes its more, sometimes its one rest stop sometimes its more. If its 100 miles I'm concerned about support/EMT's if it's 26 miles I could care less.
You can't have enough emergency people to be everywhere at once.
If that was the case they'd cancel all events like this.
I participated in a 26 mile bike and a half mile swim.
The swim was first.
I asked an official in a kayak how many emergency people are out in the bay? He said four kayaks and there were like 1k swimmers.
I said how do you know if everyone who starts finishes and exits the water? He said we count the number who started and count the finishers and if we're short we start looking ( 45 mins later).
I did the swim but the chances of them finding a person in time to rescue them or revive them was slim and none.
The kayaks were more of a "recovery " operation if needed.
Life is a risk isn't it!