My mother grew up on a farm where all but one cat was even allowed inside the house. Not sure what the survival rate was there.
When we finally got cats (I was around 11 years old and we lived in the suburbs), they were allowed to roam outside as they pleased. At that age I obviously assumed that my mom knew how best to deal with cats so I just followed her lead.
Of the 8 cats we've had over the past 16 years:
one died a few days after getting neutered (we hadn't had the chance to let her roam outside, so not very relevant)
one died after getting sick (vet suspected poison), she was allowed to roam
two went missing, both allowed to roam
two died after being attacked by a dog, again both allowed to roam
one escaped on the way to the vet (mom couldn't afford a cat carrier), she was allowed to roam but not very relevant in this case
We have one surviving cat (she's around 15 years old), and now that I know better at 27 years old, she is only allowed out into the enclosed courtyard. She used be allowed to roam and I can see that she wants to go further than the courtyard and give the chance she will but I've made a point that she stays within those specific boundaries.
My brother and his wife have three cats that they've kept indoors since they were kittens and my mom once made a pearl clutching comment of 'can you believe that they have never touched grass'. Yeah, that got a big eye roll from me.
All the people I know of who had outdoor cats, most of them, the vast majority, like 90% met bad ends.
Getting poisoned somehow, hit by cars, seriously fatally injured by local animals, accidentally falling off of high surfaces and killing or permanently injuring themselves, and the most common but arguably the worst because it doesn't provide closure: leaving and never returning one day.
Local wildlife decimation aside, I can't get myself to let them out both because I care about them too much but also because I can't handle one of my babies just up and vanishing one day.
I'm very much the opposite, I've known of many outdoor cats and none of them disappeared or met bad ends. Whereas 2/3 indoor cats I know of escaped then got lost and/or met a bad end.
But what if one year of outdoor living and exploration provides more positive experience to the cat than a lifetime of indoor life? Obviously not a provable thought, but something I consider... a ship docked is safe etc etc
There was a redux some time ago which was basically one person being a debatebro in order to avoid having to admit outdoor cats are bad for the environment (biodiversity, local fauna, extinctions of smaller animals, etc)
When my cats want to go outdoors, I let them go out into the yard—then watch them for about 30 seconds. They're such pampered indoor babies that they immediately demand to be let back indoors. Then they sit on the back of my chair for a while so Papa can protect them.
My housemate that grew up on a farm in western NSW and refuses to have outdoor cats. Between watching them slowly succumb to bites from venomous snakes to finding a python with a roughly "cat sized" bulge in its belly by the time she was 10, she vowed not to keep outdoor cats. Her parents had a different philosophy: just don't desex your outdoor cats, they'll outbreed the snakes probably.
My other housemate from Sydney was like "yeah we've had outdoor cats and they lived to be 18"
Which I only recently realised is an inverse of the usual "city folk advertise for indoor cats, farm folk just let them all out" discourse that happens online.
(I am personally allergic to cats, so my take is: don't own cats)