A single core running Python will easily handle more load than most successful SaaS companies ever reach, especially in web dev where most of the real work happens in a database of some flavor.
There absolutely are performance pitfalls, and Python is less power efficient than other alternatives running some kinds of workloads at scale, but in a ton of environments the perf difference doesn't matter.
There absolutely are performance pitfalls, and Python is less power efficient than other alternatives running some kinds of workloads at scale, but in a ton of environments the perf difference doesn't matter.