Fivetran's "dbt smart run" automates the process of running only necessary dbt models to save time and cost, eliminating the need for manual scripting or complex commands. By copying relevant tables from production to development schema and ignoring unnecessary models, analysts can focus on understanding the impact of changes without wasting brainpower. This tool provides a simple python command that handles all the heavy lifting, allowing users to specify target models and letting "dbt smart run" figure out the rest.