I think the most difficult part is the copy and pasting of 1 page at a time. I’m going through this process right now too, of migrating a raw HTML site to wordpress as a CMS and it’s taking forever. (My site may have over 1000 pages, not sure…)
Someone suggested you could do a “database dump” rather than copy and pasting but I don’t really know how to do that, so its copy and pasting tediously 1 page at a time into the wordpress create a page thing.