My understanding is that in order to place a file into a google drive, they require read and download access.
I believe this is how Google sets their access levels and does not necessarily reflect the intention of the 3rd party tool.
That being said, we block access to TPT and other sites like them. The potential for those sites to scrape data from end users and collect PII and other information is too high. You grant them access once and they continue to have access until a user intentionally removes it. If TPT (or other) were to be compromised, the impact could be pretty widespread (though likely not as widespread as PowerSchool).