I hear that Airlines performance with checked luggage is getting better.
According to a SITA Baggage Report for 2017 about one bag for every 170 passengers fails to arrive at the carousel.
Only a small proportion of those cases are permanently lost, around 1 case per 2,500 customers.
Reason for loss
Almost half of all cases of lost checked in luggage is due to the case going missing when changing planes, particularly when there is a tight connection.
I would say my experience tends to back up the figures in the last ten years and a couple of hundred flights my checked in bags have got missing 3 times.
Twice with transfer times of much less than an hour.
The other time it got held up in immigration at Los Angeles even though the transfer time was 6 hours.
Every time the bags have turned up within 24 hours.
My Travel Hacks
After 3 occurrences I now rarely check in luggage, even if I am travelling for a couple of weeks.
Even when I check in luggage I still have my carry-on with 4-5 days of clothes.
Flying to the US I aim to stay at least one night at the place where I go through immigration.