I think your number is probably too low. As a test, use noscript to block all the google assets and see how many sites you can still use. Not many.

Old ones.

It’s not an option. It doesn’t work on all our phones.

I use it for our family chat. It’s okay. The biggest issue is sometimes messages are delayed (up to half-an-hour at times). Other than that, it’s fine. It meets our needs.