Our history with Magento 2 frontend, the choices we made, and alternative solutions in Magento ecosystem: Vue Storefront 1, PWA Studio, Hyvä, ScandiPWA, Falcon.
Get your questions answered: What environment should you perform testing on? What's a good thing to do after testing? What is the value of the performance tests performed?
Performance testing is a good software development practice. What are you exposing yourself to by skipping the testing stage?
If we want our front-end to reach such excellent results we need tools which usually occur in the form of dependencies like node_modules (a lot of dependencies).