Reduce unused JavaScript and CSS

I’m trying to improve the site performance using PageSpeed. The main diagnoses are to reduce unused JavaScript and CSS.

The JS that the report points at is GTM and Cookiebot (which is a google Tag). Is there anything I can do?

For the CSS, I don’t know if there is anything I could do.

I found a few posts on the forum, but I’m still not sure what to do.

Also, I don’t understand why the performance is so different on Mobile.

Thanks for the help :)

This is the website:

Your site is well optimized. Those scripts are optional since Google Tag manager is something you set up. I don’t see an issue.

Thanks for clearing this up for me.