Why aren't .cache/rclone files being removed?

you are using some custom development version, not compiled by the rclone team.

this is the official client which can be found only here

rclone v1.57.0
- os/version: ubuntu 20.04 (64 bit)
- os/kernel: 5.10.60.1-microsoft-standard-WSL2 (x86_64)
- os/type: linux
- os/arch: amd64
- go/version: go1.17.2
- go/linking: static
- go/tags: none

notice the differences
--- v1.57.0 versus v1.57.0-DEV.
--- go1.17.2 versus go1.16.11
--- static versus dynamic