This predates me, but the toys we had to play on back in the 70s and 80s weren't much different. I feel like many things have been tamed down here in the states, litigious people are likely a large part of it.
I think the blame lies even harder on insurance corporations. Medical bills are expensive, and insurance would love to externalize the blame (and costs) as much as possible.
EU countries have public attractions that Americans couldn't dream of being allowed to experience without signing a stack of waivers beforehand.
But now if you let your kid play or walk independently, you get a lot of “why aren’t you watching your kid closer?”
It’s a strange shift.
That, and let's face it: lawn darts were just a matter of time before someone took one to the head. There were some truly bad ideas back then.