When I was younger I always found it funny how my dad would send me an email instead of just texting me. Being a silly, tech-savvy teenager, I found his use of such an antiquated and unintuitive method of communication as a sign of his use of technology primarily being in the professional world. I agreed with my teenage assessment until probably about 6 months ago.
I was needing someone to send me a picture but they had an iPhone and were used to being able to send uncompressed images to people over text. On their end the image appears uncompressed, but when I receive it, due to the limitations of SMS, almost any detail is lost to compression. I then needed to explain to them that it compresses images and that it would be better just to email me with the images as an attachment. I just gave them my email address and within seconds I got what I needed instead of needing to figure out if they had a telegram or other messaging service that allows the sending of images.
Email just works. I've been sending and receiving them since before I was 10 and it's a fairly simple concept for older folks since it serves as an electronic analog to traditional mail. You can send any media you want since attachments can be any file type. Unless you're self-hosting email, email servers rarely go down and the protocol behind email has been around since before the internet. Email is a mammoth, ancient but massive and sturdy.
My mom has been a technological Luddite since around 2008. She loved her blackberry but never really understood how to use her IPhone and still doesn't. She can text and call but that's about it. This made it hard to share anything with her because I knew she'd never see it if I texted it to her and she only ever regularly checked her work email. Since she's retired she's gotten a new email where she runs everything out of. She has always been able to operate a laptop fairly well and has been on a big psychology youtube kick. She used to tell me what to look up to find the interesting video she saw, but I never ended up watching any of them because I couldn't remember what she said. Then I saw how comfortable she was with sending and receiving emails and I told her just to email me a link whenever she saw something she thought I'd like. Sure enough now me and my mother regularly send emails of cool stuff we find unlike ever before.
Email is private. Email is not defacto controlled by any one company. Email is time tested. Email is powerful. I love email!