If you think a page is too long, there are only a few things you can do:
1. Remove content items
2. Write more concisely
3. Squish things together more (use smaller fonts, diminish line spacing, remove white space, etc.)
You shouldn’t squish things together more, unless the design is actually bad. You should always write concisely. Both of these are independent of page length, i.e., a good design supports pages of multiple lengths, and concise writing is always best. They aren’t reasons to shorten a page.
Let’s look at the other option, #1. If you think about a home page:
1. First, imagine everything is written concisely (or will be), and it has a great design (or will). So its length depends only on how many content items are present.
2. Second, imagine everything is ordered perfectly in terms of importance/priority (or will be). So no matter how little users scroll, you know they’ve always seen the most valuable content.
You’re trying to get engagement. Clicks or actions of whatever kind. Imagine the user that is on the page, but hasn’t clicked anything yet. What do you want them to do next? Here are the basic choices:
1. Reach the end of the page.
2. See more content.
#2 is almost always better for engagement, since #1 likely represents a lost user, and #2 at least gives you a chance. I can imagine a circumstance where you’ve run out of valuable things to say on the home page, of course; and in that case you have to end the page and hope users will scroll back up, you know, they were the rare visitors who were scanning to see what else was there before they clicked away. But even for them, ending the page is not really a benefit in any way.
So there’s the argument: discussions about page length are really more effective when they are discussions about
1. Concise writing
2. Priority decisions (about how to order content best)
3. Context decision (about what content belongs on any given page).