Thank you for posting that, and I am sorry. That is exactly the reply I hoped somebody would be willing to write.
Since it is my thread, my honest position after fourteen years and five cats:
I have done both. I lost two cats outdoors — one to a car, one that simply vanished. My current three are indoor-only and I will not go back.
But "indoor" done badly is a genuinely miserable life for a cat, and people who say "just keep it inside" usually skip that part. A cat indoors needs you to supply what the street was giving it:
Height. Not floor space — vertical space. A cat that can get above head height feels safe. Shelves, the top of a cupboard, anything.
A window with something happening. Not a wall. Birds, a street, a tree. This is genuinely most of their entertainment.
Hunting that ends in a catch. A wand toy for ten minutes, twice a day, and you must let them actually catch it at the end. A hunt that never ends in a catch is frustrating rather than satisfying, which is the mistake I made for years with a laser pointer. Put the laser away.
Something to destroy that is not your sofa. A scratching post that is tall enough for a full stretch and stable enough not to wobble. Most of the ones sold here are too short and too light.
And seriously consider a second cat, especially if the house is empty all day. Two cats that get on are a completely different animal to one bored cat.
The middle option is better than either extreme if you can manage it. We netted a balcony for about 9,000 rupees — mosquito netting on a frame, nothing clever — and it is the single best thing I have ever done for them. Sun, air, birds to shout at, no traffic, no thieves.