The US legal system has room for improvement. The Musk/Unsworth defamation trial is fairly simple, with few factual disagreements. Musk wrote what he wrote—court just has to decide if it's defamatory. The trial hasn't even started and the parties have already filed 134 documents.

Here's a 26-page legal brief from Unsworth's lawyers arguing about whether a particular witness should be permitted to testify. https://www.plainsite.org/dockets/download.html?id=286084184&z=69bde898

I don't know how many hours lawyers spent on that brief or what their hourly rate is but I bet both numbers are large. Multiply that by dozens of other documents filed by each side and you can see why it's prohibitively expensive for non-wealthy people to use the legal system.

I have no idea how you'd even get started reforming this. There isn't one rule dictating that court cases involve hundreds of documents. I think it's the steady accumulation of picayune rules, with no one with the incentive or power to streamline things.