It is hard to give specific advice without having a much more detailed picture of your situation.
Perhaps you can find some useful advice in these threads/posts on OneDrive throttling:
As you see above I generally recommend using tuning parameters at default values unless you have a very good (=tested and verified) reason to tweak them. From what I understand there is no need for these tuning parameters: --transfers, --ignore-existing, --retries and --multithread-cutof
You may also want to check if your speed is limited by the download speed from your Google Drive, or the resources available to your VPS.
Finally, it could be that your have a lot of files and most of them already exist at the destination, then rclone uses most of it’s time on checking – not transferring. This could also result in the picture you are describing and can be seen in your stats where checks are increasing with only few transfers.