Good (cross-platform) book management software?

My current book reading workflow is:

1) Keep PDFs, EPUBs, etc., in Google Drive (moving into Kindle as needed) 2) Make notes/highlights in Kindle 3) Parse clippings.txt 4) Save in Joplin (Second Brain)

I am looking to step up my game in steps 1, 2 and 3.

Anyone knows a solution which would allow me to: * manage my book and document collection * make notes, annotations, and highlights * parse clippings.txt from Kindle

Looked at Calibre and Polar. Happy to do further digging, but there must be a good all-in-one solution.

Thanks!