Not OP, but I wouldn't say significantly more dangerous, no. Older aircraft sometimes have to undergo modifications to mitigate faults that have been discovered

Not OP, but I wouldn't say significantly more dangerous, no. Older aircraft sometimes have to undergo modifications to mitigate faults that have been discovered over time in order to stay airworthy. By and large, a 50 year old aircraft is going to have well-understood failure modes with mandatory steps to mitigate them. The mechanism by which this is enforced is an "Airworthiness Directive" if you want to read more about it. Source: I used to fly a small 50+ year-old aircraft recreationally