https://timkadlec.com/remembers/2019-01-09-the-ethics-of-performance/
Poor performance can, and does, lead to exclusion. This point is extremely well documented by now, but warrants repeating. Sites that use an excess of resources, whether on the network or on the device, don’t just cause slow experiences, but can leave entire groups of people out.
There is a growing gap between what a high-end device can handle and what a middle to low-end device can handle. When we build sites and applications that include a lot of CPU-bound tasks (hi there JavaScript), at best, those sites and applications become painfully slow on people using those more affordable, more constrained devices. At worst, we ensure that our site will not work for them at all.