> so what am I losing?

The fact that they can use this number to correlate against contact lists collected from other people.

Now I don't think Twitch itself is doing this, but they may provide this information to marketing platforms such as Facebook which will use this data for ad targeting (and they definitely have a lot of people's contacts and can infer social graphs very well as a result).

> I don't really get this. My phone number is apparently already known by every scammer and spammer on earth, which is why I never answer calls from people I don't know, so what am I losing?

The only scammers who know my number are my phone-provider and my mom. Other scammers either never call me, or just don't know the number. Protecting your number is possible.

> Meanwhile, Twitch has had a significant bot spamming problem.

Which can be solved without this. The bot-problem is more about people not using the existing tools well and twitch sucking in their handling. Adding another features they won't use will not make anything better. Especially as the phone-number only rises the bar for bots.

The twitch tools for dealing with spam suck ass. You basically get a blacklist of words and follower/subscriber only chat modes.

You can also restrict to following-age, certified e-mail, and some more. That experienced mods do have little to no problems with bot speaks kinda for itself. Additionally, there are also a bunch of requested features on twitch-side which could had defused the problems even more, without opening the privacy-box.

Anyone who has your number in their contact list might have uploaded their entire contact list.

It literally takes only one person who has your number to reveal your number.

I’m also subscribed to a few channels. I’m pretty sure that is a far stronger signal that I’m not a bot than getting my phone number. And unlike most people, I only had 2 or 3 spam calls, and maybe 10 spam SMS on the number I’ve had for almost 20 years.

Ok so you don't want them to have your phone number but you're ok with them having your payment details?

Pretty much my PayPal account, only.

And even otherwise, any fuckups there, my bank is liable. My phone number? Outside of changing my 20-year-old number, there’d be nithing I could do.

> And even otherwise, any fuckups there, my bank is liable. My phone number? Outside of changing my 20-year-old number, there’d be nothing I could do.

Which came first? You giving your phone number away online, or the scam calls?

Scam calls just end up ringing every working number these days and if you pick up even once you're already on the list of "real people". Targeted scamming of even just 100,000 potential victims is just wasted effort when with the same setup you could do untarget scamming of 100,000,000 potential victims.

Probably not everyone has disposable phone numbers or even know how to manage them, or even choose not to do it out of a personal decision