Me? XMPP.

Most used? Depends in what circles. Telegram is popular in some. SimpleX and Session in others. XMPP in free software circles. Matrix in others.

Ah yes, the "audio casette" poster every 90s kid had

Works very well on rpi4 8GB with pruned chain stored on ssd. p2pool runs on the same machine.

Running a full node also helps the network even if you don't mine.

And you can't make noise like he did at 6am

Oh, from the same people who want you to install a mandatory app to access half of the internet? I'll pass

Do you mean you'd be linked to potential crimes of the previous owner? Well yeah there's a slim chance but then you show authorities a proof of purchase.

Or if you mean your personal privacy, that's non existent at the moment you connect to a cell network with a registered sim

If you use Linux in English, en-CA is also the best locale to use, it has 24 hour time, metric units and simplified (american) language. They will conquer the world with convenience!