When I could barely get 200 RPS from a locust instance, but 10,000 RPS from a Gatling instance, this is a huge issue if you don't have an unlimited budget.
I've compared using Locust to Gatling and the only downside is that Locust wasn't able to reach the same RPS I was getting with Gatling. It's a shame because Locust is much nicer to work with in comparison.