I don't. I've had fully indoors before, indoors/outdoors and fully outdoors cats growing up.
I have three rescues now and despite all of them having been used to being fully outdoors in two of their cases, and partly outdoors for the 3rd, they have shown no interest in going out again. One of them in fact runs like hell when the front or back door is opened. She's done her time outdoors as a stray and she has no intention of going back to that again. The other two are part Maine Coon and don't have an ounce of sense!
The other two take off as if they have been scalded if a drip of water falls on them accidentally if I'm washing my hands or something.
One of my indoor/outdoor cats years ago contracted FIV and died of kidney failure when he was just 10. I don't want that for another cat.
I have a microchip catflap from my last cat that was available for them to use if they weren't happy indoors, but they are perfectly content. They're not going to get run over, poisoned, abused, stolen, annoy the neighbours by shitting in their garden, contract diseases, go missing, get fleas, etc etc etc. I'm more than happy and more to the point, so are they.
My previous cat came to us as a stray and gradually moved in. He was neutered in his early teens and became a total lapcat! He moved indoors fully when he lost the sight in one eye and was totally content. He still got out for short periods under supervision but he didn't stay out long until he wanted to come back in. He was at least 20 when he died.