Optimization is very, very rarely completely „free“ - and usually a concious trade of some property for another trait that‘s deemed more important in a specific case.

Simplicity for performance. Code size for compilation speed. Startup time for architectural complexity. UX for security.

For a great product, you need to say „no“ much more often than not. Do one thing and do it well. Be Redis, not JBoss.

I love how this article gets down to the essence of it: https://blog.intercom.com/product-strategy-means-saying-no/