Exporting Power BI Table visual as CSV to SharePoint Folder using Power Automate only gets 500 rows

How many columns are you querying? The limit on the "run a query against a dataset" is 1million values, with values = rows x columns. If you have a lot of columns, I would reduce the number. But also try running a length() expressionon the "run a query" output in a compose action to see how many rows the output has for that action specifically - that will tell you if you if the issue is that step or another step.