The echo is used as a glorified speaker: I set it up with their Prime account and it plays all the music she could ever want through voice commands. For some reason she finds it hard to use Siri on her phone, but something about the blue light on the Echo makes it really obvious what's going on. Also, the small things make her happy like asking about the weather or the news.
The Chromebook is nice because it's super hard to mess up - you just install an adblocker and you're good to go. For someone who only uses the computer to surf the web, it's perfect. The best part is I don't have to play tech support anymore :)
I don't think I'd get either of those things for myself, but I'd definitely recommend them for your non-technical family members.