This is a very solid foundation to work with, for anyone who might have struggled with the contexts and how arrow functions, local variables, thises (hah) and prototypes fit into the bigger picture. It also clearly shows that Javascript is not the mess that it looks like from a beginner's perspective. Yes, anyone can create a 15-20 min video about how == and === can mess up stuff, how you cant just pass around a func…
But in the end of the day, stick to this car long enough and it works for you.
Plus the most popular road of the world only accept this car so take it or leave.