Hacker News Reader

It looks kind of interesting, but for me these are the bar to beat, "modern" without GUI tooling, automation and reporting capabilities just isn't interesting.

Another more basic (like OP's) but still popular one (>13k GitHub stars) and also written in Go is Vegeta: https://github.com/tsenart/vegeta

I like the simplicity and the fact that it's free and feels frills free compared to the expensive solutions posted below is refreshing.

Cassowary is the name for a well-known layout constraint solving system. Taken!

And also of a terrifying large Australian bird that should be treated with extreme caution.

Cassowary – Modern cross-platform HTTP load-testing tool written in Go