Comment by Jaepa

Actually AFIAK most of the US has moved to electronic filing, but that has actually made things more expensive. Typically courts hire out the electronic filing part. The hired companies typically collect money from both the state/county and the end user. Larger court systems like LA, NYC, and Cook are big enough to force concessions, or even fund new companies, but others have to buy into one system or another.

It would be great if a bunch of courts could band together to setup a shared open source solution, but courts at the state level are pretty fractious. And the legal system is both pretty slow and pretty reluctant to change.