Virtual machines and containers only partially solve the problem. They allow you to re-run an entire software stack easily on another computer, but that does not mean you know exactly what is going on inside that virtual machine image, how was it created, or how the binaries inside were compiled. In many cases, you’re just ignoring the problem and relying on a black box. Then you start relying on multiple VMs and containers to run ONE experiment, with very specific images versions inter-dependencies, and you’re back to square one (possibly in a worse situation).