Your local antivirus scans every byte entering your hard drive. On many systems (Norton, McAfee, Windows Defender), this scans the encrypted Google stream twice. Temporarily excluding your Downloads folder can yield a 30% speed boost.
Use a large test file (e.g., 1 GB). If you don't have one, you can find publicly shared 1GB test files on Google Drive. google drive file download speed test
A Google Drive download is a sustained, high-latency sensitive operation. WiFi 5 (802.11ac) on a congested channel will drop packets. Packet retransmission destroys speed. Your local antivirus scans every byte entering your
Why the discrepancy?
Start the download and simultaneously start a stopwatch on your phone. google drive file download speed test