This is constantly coming up and in the majority of cases, in my opinion (and others), it’s down to workflow.
A recent discussion in this thread - Layout too slow to use - #167 by LinearGraphs and the reason is because two pages are entirely a single image respectively for the representation of the particular project detail.
For sure, why can’t Layout handle large images is the cry - but all of the detail shown in the above can be done with Layout viewports.
As Dave says - we need to see one of your files.