Google page speed download speed. Why is the data different?

Question

Google

The indicators of the site https://stroy-dok.com/ in Google PageSpeed ​​are different every time, and the difference is very significant.
Checked in 3-5 minutes and constantly gives out in different ways. Checked on other sites, this is not.
Site on WordPress.
Why can there be such "leaps"?

Answer 1

Bad hosting
Uneven load on the site
Geolocation
Well, a few hundred more reasons

Answer 2

What does the server response time depend on? Only from a hosting or also from a site?
This indicator changes a lot from time to time.