Will it grow? I hope so! Started two of them, just for fun.
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.
Avocados do not breed true - you will not get a tree producing the same quality of fruit that you planted. It will be some completely random type of avocado and it's extremely rare that these end up anything besides inedible.
If you're looking for a pretty tree: go for it.
Edit: based on further information it seems that you'll likely get an edible avocado but it will have any number of random mutations from the original. In the video shown below it was mostly seed with very little flesh, for example.
If you want good avocados buy a $20 seedling and guarantee that you're getting quality.
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.
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.