Sources from when games only really had small purchases and data that's pretty much western-centric like that video are kinda worthless. Especially since the kind of games it's talking about are the clash of clans variety where you pay for boosters and stamina and such. Not actual gacha for thousands of dollars to get your UR Nico.

https://www.forbes.com/sites/johnkoetsier/2021/09/10/the-36-most-interesting-findings-in-the-groundbreaking-epic-vs-apple-ruling-that-will-free-the-app-store

Here's a much newer source where we have pretty hard data to look at. If you shuffle on down to 26 you'll see this little number:

".5% of people generate more than half of all App Store revenue. “In the third quarter of 2017, high spenders, accounting for less than half a percent of all Apple accounts, spent a ‘vast majority of their spend in games via IAP’ and generated 53.7% of all App Store billings for the quarter, paying in excess of $450 each."

Whales are alive and still the crux of the games that let them whale. Also I should clarify that the data accounts for all revenue, so the small spenders making up the other 47% includes people subscribing to services, buying books and movies, music and whatever else. If this was just gaming revenue it'd be even more dire.