For reference, though I now work in tech, I have a physics degree from a top-10 worldwide university, and reviewing linear algebra on math academy has not only been great to re-learn things I've forgotten, I'm confident that it's taught me at least a few things that I've never encountered before.
So yeah, it's legit in my book.
I also think that one of the reasons it gets such rave reviews/etc from folks using it is that it's, frankly, not that well known yet, and we users who like it _really_ like it, so we want to see it stick around and grow further for our own use too!
For reference, though I now work in tech, I have a physics degree from a top-10 worldwide university, and reviewing linear algebra on math academy has not only been great to re-learn things I've forgotten, I'm confident that it's taught me at least a few things that I've never encountered before.
So yeah, it's legit in my book.
I also think that one of the reasons it gets such rave reviews/etc from folks using it is that it's, frankly, not that well known yet, and we users who like it _really_ like it, so we want to see it stick around and grow further for our own use too!