To be a manager, you need to have an EQ. An efficient developer is more or less the worst manager because they underestimate how difficult grasping concepts, problems and solutions are. It’s difficult for folks to understand why a change that would take them an hour is taking someone 10 hours to do.
Once you crack your EQ, you need to also understand what level someone is on and how to uplift them from that level. You’ll have to give autonomy to folks who thrive in autonomy and micromanage folks who will only work when you do. Identifying the right strategy for the right person is important.
I would say very very few people in their 20s or early 30s have these traits. It can be developed, but it’s hard work to get these skills that can’t be quantified.
Another downside is, your learning takes a big hit. You’re expected to be a generalist and help folks design solutions and navigate roadblocks, even when you are unsure of the finer details of implementation.
As an independent contributor, you have the liberty to spend hours diving deep into a problem statement and technologies used. As a manager, you need to trust that the person approaching you has done their research, are able to explain what they did and why they’re stuck and then you could do some reading and lead them with a path. More often than not, this doesn’t happen. Folks are going to be very vague because they assume you know the solution in-depth and you’re just expecting them to be typists and testers.