it's hard to say without knowing the status of your site (niche + keyword research, site structuring, content quality and optimization, technical SEO, topical authority, internal linking, etc...)
Backlinks - while still needed - are one of the last pieces of the puzzle, so you need to nail down everything else before building links...
Also, those backlinks used to be good 15 years ago, nowadays they don't do shit anymore, so no surprise you're not ranking (and that's assuming that you've done everything else right first, like I said)....