I actually have an avo tree taller than me that I started this way 10 or so years ago. It is in a pot, and our climate is a bit cold for them, so I move it into the house in winter.
These are normally outside, just hiding from the worst of the winter.
This info gets repeated quite often, but when you talk to people who have gotten fruit from seed-grown avocado trees they usually say that the fruit is good.
See this video and its comment section: https://youtu.be/anUdo8tZlh0
Huh: I guess I was wrong.
At the same time the avocado he opened there had barely any flesh. It was mostly seed.
I’m not convinced that it’s worth the effort of 6+ years of growing the tree to have fruit that is inferior to a seedling you could get for $20.
I wouldn’t consider your statement wrong, but maybe just a tad bit too pessimistic. I don’t know the numbers, my point was more on the matter that - based on my readings - the chances of getting decent fruit are not too bad.
Like another commenter said: worst case you can graft a good variety onto your seedling so that you’ll get good fruit no matter your luck.