I don't think Dell installed Ubuntu on very many systems.  To top it off, it was only supported by Dell if the PC came with it out of the factory.  But as you likely figured out, unsupported doesn't always mean not working.  There's older Dell's that do a great job of running Win10 even though it wasn't listed as supported.  Some have also been installing Win11 on unsupported systems.
Been using Linux Mint based on Ubuntu for months, why it's not listed supported Ubuntu? [URL]
optiplex 9020M it's not listed supported Ubuntu