Speed up a website

I’m looking for a new solution to build website and i came across readymag.
I really like the way you can build website but i did some tests on https://pagespeed.web.dev/) with some site you can find here https://readymag.com/examples and i found readymag websites really slow.
Performance are alway around 25% to 45%. Is it a general problem? Is it possible to have performance around 80%? Do you have examples of website with good performance?

The performance may vary depending on the speed of the connection and, of course, the number of media files. For me, some of the websites have a relatively high rank (around 60). But we are currently working to improve this more.

Do you have links on what are the good practices to optimize the performance of a readymag site?

Hello! Check out our guide: How to make your project load faster