Earlier quoted context omitted.
IMO, an expensive keyboard/mouse/monitor isn't necessary for a junior to succeed. Plenty of coders learned on much worse.
I actually find it hard to switch from my "bad" hardware, I'm so used to one single small screen and average keyboard that it's how I do all my coding, despite having enough money to buy an expensive set up. I find it distracts me from my actual job, which is thinking.
To add, while this study isn't measuring actual productivity, people say they expect/feel like their productivity increased 40% with a second monitor:
https://www.jonpeddie.com/press-releases/jon-peddie-research...