Earlier quoted context omitted.
I use WhatsApp Web quite a lot, it's not perfect, but it's a nice interface to use when you have access to a desktop/laptop and can continue your conversations there.
But forget to touch your phone for a couple of minutes and the web session will automatically disconnect because the phone went to standby mode, which apparently interferes with the sync between the mobile application and the web browser session. My experience is that I can only rely on the web for a short conversation until my phone goes to sleep.
Of course now that Facebook owns Whatsapp and has decided (again) to show users what fools they where and who is the boss, all the more reasons to promote Telegram, matrix, irc etc ;-)