Downsizing PBIX file

Hello,

I'm attempting to downsize my pbix file.  My file was 3.7 MB in size and I watched it lower down to 2.4 MB in size as I was deleting queries, tables, visualizations, custom visualizations, report pages and data sources. When I finished deleting everything, I pressed save and the file is still at 2.4 MB. I've looked through this file a few times and there is nothing. Why is it still 2.4 MB in size?