When I went to college for web design, we talked about "mobile first" web design. Essentially, that means designing your mobile site first (based on what mobile users want or need) and then using that to "expand" to desktop size.
Without getting too far into the coding weeds, websites are built with multiple viewports to accommodate multiple screen sizes. Most web design platforms do this automatically - any sort of stable Wordpress theme supports mobile browsing by default. But the principle of "mobile first" likely still works even if you aren't making photoshop compositions for different screen sizes and programming CSS. Think about what your mobile users want or need, and put that in first.
For example, for a restaurant, a mobile user probably wants your location (so they can drive there), your phone number, ability to pay using Apple Pay, and your menu. That needs to be the most prominent features of your site, not philosophizing about your cooking style and the history of the famous chef you hired.
Likewise, a store site should include the location of its items in-store inside the store closest to the user. That's what mobile users want and need.
The idea is, quite simply, function over information. The old Internet was primarily an informal information repository where the point was to read information and hang out. That's what desktop users still kind of want today - to spend hours reading their way through sites and learning stuff. Or watching their way, in the case of YouTube and Netflix. Mobile users, on the other hand, want to do things with the power of information. So focus more on function and less on making your About page sound cooler than your competitors, and you'll be ahead.