You need to add an extra step which is called content review / content correction.
Try to mix paragraphs, so they don't appear in the same order as in the content you scraped from the web.
I think you could produce an article of 1000 words length for $1. Just ask someone if they can go through the article and correct mistakes, parts where it's unreadable.
I don't know how many would want to do that, but certainly there are people who are looking for a job and can do 3 articles per hour.
Even if they are hindi, they'll be able to do it. The only requirement is to speak English at B2 level.
Create work opportunities in 3rd world countries and feed that freaking google robot.
If you are dealing with products, try to make a website where you compare thousands of different products using their parameters and attributes.
List pricings and their pros / cons. That way you will up the word count.
The text can be less or more helpful to the viewer. Just make sure it's readable and that every sentence makes logical sense.
Ebay is dominating serps in my country. And the reason is that customers get everything they need there and end their journey buying.
It's also a good way to cover thousands of keywords.
The more stuff you show on the website and align it properly, the higher the chance a user will not bounce.
I think you can consider the project done if you are at 20 - 30k pages in a single niche. With some modern technology it shouldn't be a problem.