From my benchmark, i will keep using oha (https://github.com/hatoo/oha). Oha is more complete than gcannon and have similar req/s rate while handling ipv6, https, etc...
oha is one of the slowest load gen, you should look into h2load if you need h2/h3 support. I just tried oha and it pulls more CPU than the server I am testing, not to mention h2 and h3 results are just nonsense