FWIW TLS had a non negligible impact on performances at scale. Hardware improvements made that irrelevant, eventually making the switch to HTTPS by default a no brainer (or at least that's what I vaguely remember from <2010)

We could say the same about virtualization, effective containerization, layered LLM calls, and other techniques currently being explored for effective sandboxing.

There is some performance impact but modern hardware make that pretty insignificant