ChaCha20 vs AES matters a lot, because the latter is hardware accelerated on all important platforms. I did some benchmarking on this in the last year, and e.g.

ChaCha20 vs AES matters a lot, because the latter is hardware accelerated on all important platforms. I did some benchmarking on this in the last year, and e.g. QUIC transfers on the same machine peaked at 520MB/s throughput per core using AES128, vs 350MB/s using ChaCha20 (see also https://github.com/rustls/rustls/issues/509 https://github.com/rustls/rustls/issues/509).