Why are movies shown in 24fps while 60fps looks more real?

Historical reasons. Movies were originally at 16 fps, but 24 fps is more lifelike. It also gives better audio from the soundtrack. But 24 fps uses up film 33% faster, so it's far more expensive. Bumping that up to 60 fps would mean that film costs would rise nearly four-fold over 16 fps.

Film is not cheap.

Nowadays, flash memory is cheap. But I can remember buying a 250 MB (that's Megabytes not Gigabytes) flash card around 2001 that cost well over $300. We had the same cost/per video minute pressures there too.