Vapor lock can happen. It happened to us in 2017. We were crossing NM / AZ in June heading for Lee's Ferry and the Grand Canyon north rim.
We were in our '92 E250 EB Sportsmobile with the 451 V8 gas engine. Very hot day and the newly paved macadam road was very, very hot. We were on a miles-long upgrade when we suddenly lost engine power. Pumping the gas let us get off the side of the road.
For about 1/2 hour couldn't get the engine to start. Tried many things and on the 23rd or so try the engine started. Started up the grade again but made it only a mile or two until the same problem recurred.
Waited awhile and got restarted. We mad it to the top and on to a service shop eventually. Turns out the (at the time) 25 year-old fuel pump was dieing. At "normal" it could function but not when the gasoline was boiling.
So we replaced the pump which was non-trivial as it is mounted inside the gas tank. Tank had to be dropped to access the, from-the-top, mounted pump.
Problem solved and never returned. In 50 years of driving I had heard of vapor lock but never had it happen to me. Here's wikipedia link for more info but basically the fuel vaporizes from heat.
https://en.wikipedia.org/wiki/Vapor_lock