Why speed scores are different on mobile and desktop

The score depends on your website's images, CSS, Javascript code,etc

On mobile devices it is slower because the screen is small, contains a lot of content, and has to scroll continuously so it will be slower.

A score of 50 or more is the normal score of a website, and your website is ranging from 60-70 points.

If you want your website to speed up absolutely, then I recommend you to hire a website acceleration expert, of course it will be more expensive.

It will be helpful if you have someone from your side to check and fix the issues detected by the PageSpeed web.