Is this ok to hide section or elements using elementor?

Is this ok to hide section or elements using elementor, if we focus on site speed? is this cause of DOM or not?

Hiding with CSS does not improve speed.

I’m not hiding it with CSS, is the elementor doing this by default?

Elementor will hide it with CSS. The only way to improve speed if you can implement the functionality in the backend, but I am not sure if that is possible in WordPress.