These are the uBlock Origin filters i use for blocking shorts

  ! YT Homepage - Hide the Shorts section
  youtube.com##[is-shorts]
  ! YT Menu - Hide the Shorts button
  www.youtube.com###guide [title="Shorts"], .ytd-mini-guide-entry-renderer[title="Shorts"]
  ! YT Search - Hide Shorts
  www.youtube.com##ytd-search ytd-video-renderer [overlay-style="SHORTS"]:upward(ytd-video-renderer)
  ! YT Search and Channels - Hide the Shorts sections
  www.youtube.com##ytd-reel-shelf-renderer
  ! YT Channels - Hide the Shorts tab
  www.youtube.com##ytd-browse[page-subtype="channels"] [role="tab"]:nth-of-type(3):has-text(Shorts)
  ! YT Subscriptions - Hide Shorts - Grid View
  www.youtube.com##ytd-browse[page-subtype="subscriptions"] ytd-grid-video-renderer [overlay-style="SHORTS"]:upward(ytd-grid-video-renderer)
  ! YT Subscriptions - Hide Shorts - List View
  www.youtube.com##ytd-browse[page-subtype="subscriptions"] ytd-video-renderer [overlay-style="SHORTS"]:upward(ytd-item-section-renderer)
  ! YT Sidebar - Hide Shorts
  www.youtube.com###related ytd-compact-video-renderer [overlay-style="SHORTS"]:upward(ytd-compact-video-renderer)

I think these were on the uBlockOrigin subreddit, couldn't find the post