Fixing Above-The-Fold Content Problems?

Running 2.4 as a reference. I’ve had several audits run on my site from time to time whether I was operating with 1.9 or 2.x and they keep bringing up, “above-the-fold content”. They say “the most important content SHOULD be above the fold. Apparently mine isn’t. Apparently it’s a huge deal.

Excuse my ignorance.

1. What does this mean?
2. Is there a way to check if this is STILL a problem today by scanning a page/url for content below or above “the fold”?
3. How is it fixed/corrected?

Does it typically just affect homepage’s only? All pages?

This is a problem as I’m told but I can’t get clear advice on how to resolve it without paying the company a fortune to fix the problem. Is it a big fix that requires a ton of work and a deep understanding of Magento?

Thanks!