These "clean code" principles should not, and generally are not, ever used at performance critical code, in particular computer graphics. I've never seen anyone seriously try to write computer graphics while "keeping functions small" and "not mixing levels of abstraction". We can go further: you won't be going anywhere in computer graphics by trying to "write pure functions" or "avoiding side effects".
These "clean code principles" are, however, rather useful for large, corporate systems, with loads of business process rules maintained by different teams of people, working for multiple third parties with poor job retaining. You don't need to think about vector performance for processing credit card payments. You don't need to think about input latency for batch processing data warehouse jobs, but you need this types of applications to work reliably. Way more reliably than a videogame or a streaming service.
Right tools for the right jobs, people need to stop trying to hammer everything into the same tools. This is not only a bad practice in software, it's a bad practice in life, the search for an ever elusive silver bullet, a panacea, a miracle. Just drop it and get real.