No, actually, I don't think my indoor cat would be happier if he could free-roam. For one thing, the feather-toys inside have never died on him mid-playtime, and I feel like that might be a disappointment
As though predetermined by fate I awoke this morning to Ollie standing on top of my chest, fur slightly-damp, and when I went downstairs to investigate whatever shenanigans he had somehow gotten into I found that the back door had somehow blown open in the night.
He has never had unsupervised access to the outdoors before but it appears he stepped outside, found it to be raining slightly, and decided "fuck this shit, I'm getting Dad"
I love my fragile son