I have done a POC of testing a Desktop eCommerce website on a mobile browser, using Selenium 4.x alone, running the tests using Browser Emulation using Chrome Developer Protocol (CDP, now going to be BiDi). I used completely Selenium 4.0, and Java alone as it is basically a Desktop website running on mobile browser.

Now the Client wants the same tests run on real Android/iOS devices attached to the PC using USB ports.

There is a similar question on Stack Overflow. It helped me a lot as far as high level direction except changing some deprecated classes for using Selenium 4.x

I am looking for more updated documentation/suggestions etc.,