WhatsApp would still be plenty incentivized to make their software secure. They understand that this wouldn't get rid of the exploit market, or state actors. I'm sure WhatsApp has been focusing a lot on security lately because of the brand damage.
Even if it wasn't effective in practice, entering this lawsuit can be seen as a message to users that WhatsApp is serious about protecting people's privacy.
Setting a precedent here might force remaining actors to stay shady instead of acting in the open, which would make it harder for them to operate (so they'd be less effective).
However, I have no idea what other consequences a precedent here might have. Definitely interesting.
Even if it wasn't effective in practice, entering this lawsuit can be seen as a message to users that WhatsApp is serious about protecting people's privacy.
Setting a precedent here might force remaining actors to stay shady instead of acting in the open, which would make it harder for them to operate (so they'd be less effective).
However, I have no idea what other consequences a precedent here might have. Definitely interesting.