Could you please check how it works with some default WordPress themes like TwentyTwenty or WooCommerce Storefront to understand is it our theme issue or not?
Please, activate our theme on the example domain so we can compare the loading time. Also, send us the admin access so we can switch between themes and test.
We tested with the default theme it works slowly there also https://gyazo.com/a9b55533ac13904db40f502f6af9e447
In addition, it works not stable. It means that it might be faster sometime and sometime slower. It is definitely something wrong with the server.
It should work fast even with low CPU and ram. It depends on the server configuration mostly. Yes, we use Hetzner but we also got high results on other hosting as well.