I like the great outdoors but I live down a cart track near fields where it is not too dangerous (except for foxes). And I come in at night for my last meal, so that I don't stay out too late - which cuts out some of the risks of being run over or eaten by a fox. Most cats would like this kind of lifestyle.
But it is safer indoors, definitely. Safe from predators like stray dogs, coyotes, foxes. Safe from traffic. Safe from disease caught by fighting with other cats. If indoor life is boring it is the fault of your humans. You should have lots of toys, a different one every day, lots of games with fishing rod toys when your humans are watching TV, and you should hunt for your food.
Hunt? Well hunting is what we cats do and it is what I do outside in the garden and fields. You can hunt too if your humans stop putting any food into a bowl. They should put it into food dispensers (look here for ideas), or scatter it so you have to run for it, or hide it round the house. Or build a feeding pole! Or by the Funboard - video here. That way you can keep busy hunting for food even when they have gone off to work.
I hope you have chosen rich humans... If so, they could build you a catio or even just fence in the whole garden - ideas here. There's a photo of a catio here. That would keep you safe and give you some fresh air.
So if they won't let you outside, get them to start doing what humans should always do - make you happy with an active lifestyle. It is their job to make you happy.