I registered copyrights for software I wrote when I was a 12 y/o kid (a kid who was interested in intellectual property law, to be sure, but still a kid). It wasn't that difficult.
That would get expensive fast for anyone remotely prolific. Not every work needs protection, and it's impossible to know which does before it becomes commercially interesting.
I can't imagine, under a hypothetical copyright regime requiring registration that enacted today, anyone would be mailing in paper copies of "Form TX" like I did in 1989. There would absolutely be a more streamlined method of registration.