I spent lots of time trying to get my ESP32-WROOM to reliably load code from VSCode/PlatformIO. Most of the web discussion focuses on hardware changes: more bulk capacitance, timing on EN line, but none of that helped. What ultimately made flashing 100% reliable was simply downgrading from the esptoolpy version 2.6 that is the default to 2.1 by adding the following to my platformio.ini in the upload section:
platform_packages = tool-esptoolpy@1.20100.0
With that change, every download was fast and reliable at speeds up to 430kbps.