When picking avacados to buy, aim for the ones that are longer than they are round. If it's as round as an orange, you're going to get this kind of all-pit bullshit.
To save people a click: that video is by a channel notorious for cooking videos filled with jokes. Avocado seeds don't have more avocado in them, it was a joke. The guy cut a seed open, carved out a cavity inside each half and filled that with avocado for the bit.
Not always true and depends on the particular type of avocado. I’ve gotten haas that are round, and have tiny little pits (about the size of a big marble) and others like your pic. I’ve also got the standard looking haas with a HUGE pit too. It’s the luck of the draw.