I use one a lot that must be 100 years old, can't remember what it says on it. I've always thought more about what it's hanging from than how strong it really is.
Funny you mention that it takes two people to hang it. That 1/2 ton hoist has gotten heavier over the years, it’s very possible its in its final resting spot
I've had several chainfalls, never gave me any trouble. Looks like those chains were twisted. Probably dirty and needing lube too.