All 3 billion Android devices in the world. It’s pretty crazy when you think about it. Also 96% of the top 1 million web servers and all of the 500 fastest super computers (excluding quantum) in the world.
Both WhatsApp and Telegram suck. Just like any other messenger that’s either proprietary or not end to end encrypted. Signal is clearly the best choice.
There are solutions for all of these issues. You can use alternative frontends like Invidious or Piped, dedicated desktop apps like FreeTube or NewPipe and Libretube on Android to access YouTube without ads or tracking. You can also use throwaway email addresses to access websites that demand your email and there are privacy frontends for most social media sites (e.g. Libreddit for the site that shouldn’t be named, Nitter for the other site that shouldn’t be named, Proxitok for Tiktok, Proxigram for Instagram, etc.)
Maybe they don’t live off of benefits, but they get massive tax benefits. In fact, the government loses way more revenue by not taxing billionaires properly than by helping homeless people.
What about just not using a proprietary client for an open source social media platform? You’ll find amazing FOSS Lemmy clients as well as a whole lot of other FOSS software on F-Droid. It’s the best source for Android apps. Thunder is my personal favorite.