On the contrary, Junk folder is only useful if you go there regularly and check that non-junk mail didn't get there. Especially for services that have too much false positives, like gmail.

Otherwise you can just drop the mail you'd put there immediately on reception and not even store it.

I'm particularly wary of mail filtering that seems to always put mail from a sender that hasn't been seen before into junk... which certainly puts a bit of a chilling effect on communcation.

That's not at all how my cellphone works. This has been thankfully the case recently when a hospital contacted me to notify that they had admitted my grandmother.

It's not safe to block calls from unknown numbers if you have people that may depend on you.

Email is much less likely to be critical, but there are still occasions when you may be contacted with important information by addresses you didn't think to white list.

There was a time not that long ago when we didn’t have caller ID and we actually answered ALL our phone calls

It's the difference between a social network decicated to exchange in a bubble and a truly universal communication service like post, phone system or email where anyone can reach anyone without subscribe to same/any service, without being "friend" or trusted.

you mean like Skype. There's nothing specially 'email' about this other than it is a bad mix up of a P2P communication app and a supposedly 'trusted' version of SMTP.