I have played around with Stem creation on cloud based sites before but not using a local running program.
OpenVINO is a plug in which runs in Audacity entirely on your local machine. Once installed it will breakout any music file in up to four stems. Drums, Bass, Vocals and other instruments. IMO, it does a pretty good job with a minimum of artifacts. So if you have a song where you just can't quite make out some of the details, it might be worth a try.
There are three other modules included besides the music splitter, Noise Reduction, Speech transcription and AI music generation. No messing about with logins, demos and the price is right......free.
It's fairly easy to install into Audacity and can be found on Github along with instructions. It only works with Audacity v 3.4.2 and higher.
https://github.com/intel/openvino-plugins-ai-audacity/releases