Google: If You Need To Manually Submit Pages To Index Then You Need To Improve Site Quality...John Mueller from Google said on Twitter "If your site relies on manual index submission for normal content, you need to significantly improve your site."
He is saying if Google will not pick up your pages to be indexed without you using the request indexing feature in Google Search Console, then you have bigger site quality issues. John added "Search Console does not fix your site, you need to do that yourself."
Forcing a page to be in Google's index will not result in that page ranking any higher. It just might prove to be a waste of time. Why push something into Google's index if the page won't rank well anyway. Instead, work on making the page better, so Google wants to rank it higher?
(bolding by yours truly)
All it takes is one link from an existing site for the search bots (all of them, not just Googlebot) to follow to start the indexing process. The rest is up to you. It might be slow but it works.
Have you manually submitted a site to Google or did you get indexed by being found?