Mrcheerful used his keyboard to write :
I would tend to agree, but only from an 'at the roadside' repair point of view. Modern vehicles are massively more reliable and durable than their earlier brothers, both mechanically and electrically. The problem being that most faults on modern vehicles are often major ones, requiring a garage and parts to sort out.
If you were to run 100 modern cars versus 100 old type cars in the same conditions, I'm certain more of the 100 modern ones would arrive at the destination.
30 years ago I would usually carry a full tool kit along with some spares - not just in case, but because I would expect to break down if I did enough mileage. For the last 20+ years I have not had any breakdowns at all, excepting for tyres. Instead and in anticipation of any breakdown being much more serious, I have had breakdown cover to get me towed to somewhere repairs can be arranged.