Welcome to the Q&A Forum

A few unordered thoughts: I don't think that the URL alone is what's causing the blog to outrank the homepage. Some causes are probably that the content is better suited towards "plastic cups", the on-page optimization is more specific towards "plastic cups", or that the blog post has more internal/external links pointing to it. Also could be a combination of any/all of these. If your main topic for the site is around plastic cups, then the homepage should probably rank for it. In which case you could 301 the blog post to the homepage, and ensure that the homepage is targeting "plastic cups" as best as possible and that the content suits that keyword well. If the main topic for the website isn't plastic cups, then I would argue that it's OK that the blog post ranks—take that and use the homepage to target something else entirely and just make sure the CTA on the blog post is appropriate. The way to let Google know your homepage is most relevant for the term: Redirect blog post to homepage. Ensure homepage has well written and helpful content around the topic. Ensure homepage targeting (title tag, h1, etc) is focused on the topic. Re-submit sitemap to Google for re-crawling and wait for a few days/possibly a week. Hope that's helpful!