25 usable pins sounds bizarrely low to me. At the die size of 3.2mm x 5.3mm, regular old wire bonding in a QFP package should get over 100 pins easily. It's also easier for end users to handle a QFP. Am I missing something here?

Wlcsp is done before cutting the wafer so it doesn't require a separate packaging line.

I see! Thanks.

Expected usable pins is more ~ 40

@Kevin Baragona Main reason for wlcsp packaging is reduced parasitics for high speed signals like SERDES etc.