[shawnz]

Whatever eventually displaces JMeter has got to start somewhere.

[RandyRanderson]

Can you even 'replace' an open-source soln with a closed-source one?

If so, there are already many better "replacements" like loadrunner:

https://www.softwaretestinghelp.com/loadrunner-alternatives/

[sciurus]

I think extensible open-source load testing tools like https://k6.io and https://locust.io are already replacing JMeter.

[exdsq]

Yeah locust is great - used it for fairly complex loadtesting of a blockchain and enjoyed it. Gatling is another good one if you like Scala.