No keyword focus. Pages written about the business rather than the words customers type into Google, so there is nothing clear for Google to match.
Technical barriers. Pages blocked from indexing, broken redirects, duplicate pages, or a slow mobile site that is harder to crawl and rank.
Thin content. One page trying to cover every service, or short pages that say little a customer couldn't find anywhere else.
Little authority. Few reputable sites link to or mention yours, so Google has less reason to trust it over an established competitor.
A neglected Google Business Profile. For local searches, an incomplete profile with few reviews keeps you out of the map results.