Packages that aren't native to Tumbleweed are available in Discover as Flatpacks.
You're probably trying to look for software "the Windows way" of downloading the sw from a website in which case you mostly see .debs and .rpms but that doesn't mean it's not available in the tumbleweed repos or Flatpacks if you search Discover.
Niche stuff not available in the official repos or Flatpacks can be found in the OPI(similar to Arch AUR) where the proprietary codecs also are.
Can you stop dodging the question and changing the topic? You still haven't mentioned what software you haven't found on Tumbleweed but exists on Kubuntu.
Packages that aren't native to Tumbleweed are available in Discover as Flatpacks.
You're probably trying to look for software "the Windows way" of downloading the sw from a website in which case you mostly see .debs and .rpms but that doesn't mean it's not available in the tumbleweed repos or Flatpacks if you search Discover.
Niche stuff not available in the official repos or Flatpacks can be found in the OPI(similar to Arch AUR) where the proprietary codecs also are.