On a 10" tablet, which I have, the web browsing experience is exactly the same as on a desktop PC. I don't think they should be lumped into the same category as a 3"-4" phone screen.
Google can't seem to decide if my website http://www.montereypeninsula.info is mobile friendly or not. On my Ad Sense page some days Google gives me a 4 out of 5 mobile friendly points, and on other days it only gives me 1 out of 5, then goes back to 4 even though nothing has changed. I don't have a smart phone, but my dumb phone with a 2" screen has a browser and my site is quite readable without any side to side scrolling that Google frowns upon.
I never got into using the fancy bells and whistles many modern websites use and are now having to simplify. Many fancy websites are starting to revert to late 1990s formatting norms to comply with Google's mobile friendly standards. My site, which hasn't changed much in its 18 years of existence, doesn't look obsolete anymore! But I'm not sure that dumbing down websites to fit the smallest screen someone might use is necessarily a good thing. On my desktop PC many websites looked stripped-down now. Other websites "see" my 10" tablet as a 3" phone and will only let me look at their dumbed-down mobile version even though the full site would work just fine. It's really annoying.