Just feed a cat and it will always return. A cat is not cattle; you don't need to track a cat.
True, if they are ok.
Cats rarely get lost, unless some mafia cat attacks/chases them, then he might end in some remote area and/or hurt and not be able to return.
I lost a cat that way, we normally let him go to the outer windowsill, as we lived at the lower level, there was just ~6ft/2m to ground, so no risk of falling, in fact he ocassionally went away to see the world or try making friends with ferals.
Then a very huge black feral appeared, all cats flew away and he became the only one around.
My cat was a neutered male, so he didn't have any of the agressiveness, behaved like a big sweet kitty, so he went outside to salute him and got badly beaten, had to take some surgery because he got a deep bite at the base of the tail, got badly infected, was hard to detect with all that fur, until few days later a potato-sized lump appeared.
The vet said it had become necrosis, but it wasn't very extended so it looked like it could go well, but few days more and it would have extended to the spine, that would've been really bad.
Luckly he did great and healed in no time!
We didn't let him outside anymore, the poor thing cried all day wanting to outside.
Once we opened the windows for venting, accidentally left the door open without noticing, he probably took 2 nanoseconds to fly away and start smelling/watching everything.
Sadly that was the last time we saw him.
So yeah, a GPS tracker would have been be a great thing. Sadly not a common thing in 2003!