Firefox extension that fixes this issue: https://spectrum.chat/figma/feature-requests/zooming-speed-with-ctrl-mouse-scroll-on-firefox-differs-from-googles-chrome~250fac37-73e9-4319-b38a-297bf4db5843
It makes scroll in linux faster for figma.com site.
Extension link: https://addons.mozilla.org/ru/firefox/addon/scroll-figma/