There’s really no perfect standard for length in any format. I read on my phone so one page to you may be 5 pages to me.
I could see the word standard itself being the only reliable format. Like Standard Ebook uses as a measure for book length, but it may be hard to adopt generally.
“I read 567,000 words last month,” may come off oddly. But certainly not unreasonable.
“Let’s do a 200,000 word/month challenge!”
As a mod on a few garden and science subs at that time, they were pernacious and ethically inept. They would associate anything anti-pesticide or GMO with being an anti science quack. And they would dog pile on poor individuals expressing concern.
I had several debates with them, often reported them for brigading, and ultimately had to ban them.