It's not just the applications, the installer doesn't even start up with 1GiB of memory. With 2GiB of memory it does start up. You could (well, I would :) ) blame it on the Gnome desktop, but it is very different from what I would have expected.

I just tested this with 25.10 desktop, default gnome. With 24.04 LTS it doesn't even start up with 2GiB.

So, you mean when RAM is 2 GiB with 25.10 the installer started up but didn't with 24.04? What about being able to install and then boot the installed Ubuntu?