Why do Binance stake pools pledge nothing?

Question

Binance runs 62 pools close to saturation. See AdaPools: https://adapools.org/groups/binance-20. But I am more surprised that every one of them has only 2 ADA in pledge! I am confused why Binance does this since nothing-at-pledge pools are supposed to only earn 77% of fully-pledged pools' rewards. Binance isn't dumb (or so I think) and they have dominated staking for a while, so they should know this better than me. If there's any technical reason behind this, could someone share them so we can better run our own pools? Thank you.

Edit: most Binance pools only have 5 to 10 delegators: https://cexplorer.io/groups/binance though all of them are public pools. In addition, they are promising 15% yields on Cardano so they are probably using a custom system anyway.

Related questions:

1. Why do Binance run 62 pools if it is an exchange?
2. Are there any negative effects of having too many stake pools run by central exchanges?

Answer 1

DISCLAIMER: There is no official statement from Binance on that topic, so I can only speculate.

Binance is running (similar to other big exchanges) a very large amount of pools. To be able to provide a meaningful pledge on all of them, they would have to hold a large amount of ADA. This would expose them to the risk of market volatility and also lock a substantial amount of funds that they can't use for anything else.

They can't increase the pledge on some of the pools without increasing it on all of the pools, because this would be unfair for their customers. (Some get better rewards, some worse).

Therefore I think the only logical thing to do for Binance (or other big staking providers) is to simply accept that the pools are earning less than the maximum amount of rewards. They still earn more than enough for it to be a profitable business due to the large amount of controlled stake. The people coming short are their customers, but they are probably not aware of this.

Another option would be to take the pools private (100% margin fee) and distribute the rewards using their own custom system. But this would increase the operational cost.