Do you optimize websites for older browsers and mobile devices?

Question

css

Hey!
I believe that optimizing sites for ancient browsers and mobile phones, and besides, smart watches (link to the article from Habr) is not entirely necessary. Is it enough to make the site rubber? I don’t think about adapting to old browsers at all, doesn’t it interfere with moving forward?
What solutions are there to eliminate most of the routine optimization tasks and are you optimizing your work?

Answer 1

No. We write to the user with an old browser that the site does not work correctly for him and offer to update the browser

Answer 2

Old browsers are not supported. Scoops on the Internet, which are in the modal window “A new version of Google Chrome has been released. Update now? press "Not now", are not needed.
Mobile devices - we support, but again, only lastgen.

Answer 3

Depends on the project. If the client has visits from old browsers, then we do for those from which they sit.
Usually - IE9+, everything below is discussed separately.
For IE8 we take +30% of the project cost, etc.
Putting a stub is nonsense, the site must be available.