I think 'at the time' they were 'fit for purpose', could be 'played with more' but more aimed at younger generations not yet able to respect the finer points of 'don't hold here', 'don't touch there' that's required with the super detail of today.
They were obviously more able to withstand knocks, bumps, shocks of general playing or parents cleaning up, knocking them off the tracks ...
The market requirements, standards, call it expectations are vastly different now, with the rivet counters winning ...
Different times, different production abilities, different expectations, different requirements.... and not that much difference in price when inflation corrected!!
Al.