What software doesn't run with 4GB of ram is the real question.

Most individual programs will run with 4GB but you won't be able to have multiple open at the same time.

It is really only a problem with electron apps that you can usually easily replace with opening the corresponding website on a browser and have more native and less memory hungry alternatives.

If you favor them over a huge DE, a distro with a lightweight window mamager / wayland compositor will only use around a hundred of megabytes, so with 3.8-3.9GB you have plenty of memory to run apps running on regular OS toolkits.

And having a bit of hygiene like exiting apps you are not actively using goes a long way.