Most people I know have switched to WhatsApp exactly for the reasons you mention. I'm not a very social person, yet I'm already in multiple chat groups: 'family', 'siblings', 'social groups', 'activity groups'. It's the same for almost everyone I know.

Feature-wise, I'd much prefer everyone switch to Telegram, but I wouldn't be surprised if these features come to WhatsApp soon. Main reason I think they haven't is that Facebook might still try to make their main product 'work', or perhaps some kind of anti-trust issues?