About 'no fees at all for sending crypto from one Paypal account to another.' when you are not actually transferring the bitcoin to another wallet and there is no network fee to pay for the transaction it's not really surprising to see them taking no fee for their internal transactions because it's not a big deal to see them doing this for the users.
But the most interesting part is the second one, about fees to send from your Paypal account here is where people should pay the transaction fee but they will not take any additional fees.
Unfortunately there are some places that still charge this as a "service fee", but the competition made it a bad thing. If all websites charged this, then all would continue to do it, but when a few big names start doing it for free, it became a forced thing to do for free otherwise everyone would go there.
Like Binance does user to user transfers for free, the network fee is still taken, but if it is another user on the receiving end, you could get the network fee back, or send that to the receiver as well. When even the biggest one which is Binance does this, Paypal sort of had to do it, but still some charge you for it in the name of providing a service.