Relevance
Your profile should explain what the business actually does. Accurate categories, services and business details help Google understand how it matches a search.
Distance
Where the searcher is matters. More reviews do not eliminate the role of location in local results.
Prominence
Google considers how well known a business is. Reviews and ratings can contribute, alongside other information about the business.
Measure interest carefully
Calls, direction requests and website clicks tell you about profile activity. They do not independently prove completed purchases or walk-ins.
Source: Google guidance on local ranking