I have no idea what "professional work" could possibly mean in that sentence. The things that you have deemed superfluous are the tools of the trade. We don't use every tool on every job, but when we do use them, its because they make our work easier!
Someone who doesn't know that lodash exists will reinvent lodash, and do it poorly because JS has crazy edge cases.
Someone who hasn't experienced Bootstrap's crazy, nested selector hierarchies and pseudo-selectors will end up creating their own CSS hell.
Someone who doesn't know about flexbox will end up writing who knows what instead of 'justify-content: flex-end' (or even vertical align).
react-router has been a disaster, but that doesn't mean that rewriting it yourself will be great.
Someone who doesn't know the purpose of Redux will eventually end up with spaghetti callbacks or a building a much worse clone.
Every single project I've seen that uses Redux without Immutable ends up creating a worse Immutable.
Could someone build something without any of this knowledge/experience and throw it on the Internet? Sure! Would I be happy inheriting (or even using) that "reasonable application"? No!
Someone who doesn't know that lodash exists will reinvent lodash, and do it poorly because JS has crazy edge cases.
Someone who hasn't experienced Bootstrap's crazy, nested selector hierarchies and pseudo-selectors will end up creating their own CSS hell.
Someone who doesn't know about flexbox will end up writing who knows what instead of 'justify-content: flex-end' (or even vertical align).
react-router has been a disaster, but that doesn't mean that rewriting it yourself will be great.
Someone who doesn't know the purpose of Redux will eventually end up with spaghetti callbacks or a building a much worse clone.
Every single project I've seen that uses Redux without Immutable ends up creating a worse Immutable.
Could someone build something without any of this knowledge/experience and throw it on the Internet? Sure! Would I be happy inheriting (or even using) that "reasonable application"? No!