For windows / linux I've found the freetube app to provide a lot of sane controls. I can block channels as needed, block shorts, hide profile pictures of commenters, and a lot of other quality of life things. You can even set a password for the settings as needed.
Otherwise in the browser (firefox) I've been somewhat succesful in blocking youtube shorts with ublock origin filter rules:
www.youtube.com##ytd-rich-section-renderer.ytd-rich-grid-renderer.style-scope:nth-of-type(1)
www.youtube.com##ytd-rich-section-renderer.ytd-rich-grid-renderer.style-scope:nth-of-type(2)
www.youtube.com##ytd-rich-section-renderer.ytd-rich-grid-renderer.style-scope:nth-of-type(4)
www.youtube.com##ytd-guide-entry-renderer.ytd-guide-section-renderer.style-scope:nth-of-type(2)