I don’t think it is true at all.
The recommendation algorithm they implement is a choice they make, it is not that if they had more engineers they would deploy a “better” one.
Every recommendation algorithm is, in the end, “bad” in some way.
The TikTok algorithm was considered the non plus ultra among recommendation algos; now you cannot watch a video of a cat on TikTok for more than 5 seconds that the next 50 videos they serve you are of cats.
The Netflix recommendation algorithm has not shown something to me that I considered hidden but interesting in years. They just show you whatever they want to push, mostly (I worked there).
You buy a pan to cook steaks on Amazon and, for some reason, the algorithm recommends to buy it along with stroboscopic lights.
I didn't say they were all working on the algorithm, there were a lot of people working in various content-related jobs: moderation, algorithm, partnership management with content creators, ad sales, and more