My fix to this annoyance:
(uBlock Origin)
[[

	github.com##:matches-path(/^\/+(?:orgs|community)\/+community\/+discussions(?:\/+categories\/+[\w\-%]{1,3060})?\/*(?=[?#]|$)/i) div.Layout-sidebar:has( include-fragment[src*="/community/discussions/leaderboard"] ):remove()
	github.com##:matches-path(/^\/+(?:orgs|community)\/+community\/+discussions(?:\/+categories\/+[\w\-%]{1,3060})?\/*(?=[?#]|$)/i) div.Layout div.Layout:remove-class("Layout")

]]
    Know not who has coined such thoughtless "grid" layout...

    See also: https://github.com/orgs/community/discussions/5972#discussioncomment-7770150

    Strangely doesn't work:
[[

	/github\.com\/+(?:orgs|community)\/+community\/+discussions(?:\/+categories\/+[\w\-%]{1,3060})?\/*(?=[?#]|$)/##div.Layout div.Layout:remove-class("Layout")

]]
    While this one does...
[[

	/(?<!\.)(?:vscode|github)\.dev\/*(?=$|[?#])/##*:style( color: red !important; )

]]


    Additional anti-annoyance:
[[
    github.com##:matches-path(/^\/+[A-Z0-9](?:[A-Z0-9\-]{0,37}[A-Z0-9])?\/+[\w\-.]{1,100}\/+discussions(?:\/+categories\/+[\w\-%]{1,3060})?\/*(?=[?#]|$)/i) div.Layout-sidebar:style( max-width: 256px !important; )
    github.com##:matches-path(/^\/+[A-Z0-9](?:[A-Z0-9\-]{0,37}[A-Z0-9])?\/+[\w\-.]{1,100}\/+discussions(?:\/+categories\/+[\w\-%]{1,3060})?\/*(?=[?#]|$)/i) .discussion-spotlight-container:style( height: auto !important; )
    github.com##:matches-path(/^\/+[A-Z0-9](?:[A-Z0-9\-]{0,37}[A-Z0-9])?\/+[\w\-.]{1,100}\/+discussions(?:\/+categories\/+[\w\-%]{1,3060})?\/*(?=[?#]|$)/i) a[data-target="discussion-spotlight-container.mainLink"]:style( font-size: 75% !important; -webkit-line-clamp: initial !important; )
]]
(adjusted sidebar width; also reduce the thoughtless clipping in Spotlight cards)

    And another:
[[
    github.com##:matches-path(/^\/+search\/*(?=[?#]|$)/i) div.Box-sc-g0xbh4-0.fpwPAg
]]
(similar situation on [ https://github.com/search?q=involves:MasterInQuestion ] alike)

    Before-After: