They might’ve done so out of necessity. I don’t know if the dev(s) of the Simple Tools apps were working on it full time, but if they were and just not enough contributions were coming in from it… Well everyone has to eat.
As the saying goes, “everyone has their price”. It’s easy to condemn the developers for their choice until you’re in the exact same scenario as they were. Whether that’s because they were starving, or even just offered enough money to make their lives a lot easier - not too many people would turn it down.
This doesn’t read as a global Blocklist for all Android phones in the world. It reads more as a local database/API for blocked numbers on your phone.
So blocked numbers would theoretically be applied to your messages apps and other “telephony” based apps that use phone numbers such as WhatsApp (should said apps implement the API).
Google already seems to have a spammer database for numbers, though I’m not sure if that applies to just Fi users, Pixel users, or anyone who uses the Google Phone app. If I have call screen disabled, I’ll see numbers on an incoming call have a red background with a “likely spam” description.
But based on the comments on this post, I feel as if I’ve overlooked something in the article here (I’ve just woken up so it wouldn’t surprise me) - is there a mention of it being a worldwide list?