It is for professional and experienced traders who know exactly what they are looking for. They don't let emotion affects their decisions like newbie traders and they focus on some indicators, information they see fit. Unlike newbie traders, who read many useless information, over attach many indicators on their charts that all together affect their thinking about the market and movement of a coin. With newbie traders, more screens, more emotion, more bad decisions.
Beginner traders will of course be very different from traders who are already professional, because most beginner traders have to spend more time learning while using their money to try it, so obviously those who are still beginners will have more screens and emotions that can arise. as a result of some of the mistakes they made. Because even those who have become professional traders have also made mistakes in the past when they were still learning like beginners today, so this is a comparison of two traders with different levels of knowledge.
Its overkill i would say on which a noob tending to make some multiple monitors just to make out some trades is never been that efficient or basically you are still wasting money since you cant really be able to utilize those monitors for your advantage on which you would really be still that focusing on learning those basic stuff on a single monitor which i should say that it would really be just that enough.
2 monitors for a professional trader would really be that enough but just like the rest been saying that it would really be entirely be depending on someones preference because we know that there are people who do have multiple jobs specially to those who do WFH which it is really that necessary to have those multiple monitors for best user experience and that comfort which it gives but somehow
you would really be needing to spend some extra for that kind of benefit on which it would really be still depending with your budget.
The best thing to put focus on is on how you would really be able to make yourself that learning without needing to spend much not literally on trading capital
but on the resources that it really needs.