Isocons is a dedicated isometric icon set, now past 1,000 icons, drawn in three perspectives and two corner styles rather than the flat/outline look most icon libraries use.
Isometric is a narrow, hard-to-fake style: having a set purpose-built for it saves the work of redrawing flat icons into 3D perspective by hand.
Fits dashboards, onboarding illustrations, or marketing pages going for a dimensional, isometric look rather than standard flat UI icons.
Licensed CC BY 4.0, so attribution to Isocons is required even though the icons are free to edit and use commercially; a Figma plugin and on-site stroke/color editing are also included.