static page without any plugins involved

I guess you can use https://projectdmc.org/plugins/freesoul-deactivate-plugins/ to deactivate all the plugins on that “empty” page.

Obviously in a empty page plugins still are being used.

That’s not necessarily true.

And a million different things can affect site performance… not just plugins: traffic hosting, theme, content on pages, and even the amount of traffic getting to the site.

Please review the official WordPress performance optimization resource below:

Optimization

Hello @kirilb

It’s odd that even a plain page is slow. I suggest checking with your hosting provider. When your site hits resource limits, the server can slow things down until it normalizes. They can help review your server’s health and sort out any issues.

this freesoul plugin is just amazing! I tried it and it improved “Largest Contentful Paint” from 5 to 1.5 sec each page! Yes it took time to figure out which plugins are required for which page, but works!