Not EM but I was made a team lead of a small team. I still got to write code, but was also to delegate tasks to other team mates, hold 1-1s, sit in more "management-y" planning meetings, do a lot more JIRA wrangling for multiple contributors, etc. I had expressed my hesitation since I really liked being an IC and wanted to continue developing in that direction, but was open to giving it a solid try - you never know, right? So I tried it for a few months and ultimately decided that, at least at the time, it wasn't for me. I talked to my TD and line manager about going back on the IC track.
The way I approached it was:
* Making clear that I greatly appreciate the opportunity to try this new role and did give it a _proper_, fully committed try.
* Clearly expressing what exactly isn't working for me personally about it, and why I think I'd be both more happy and more useful as an IC.
As part of the second point, I mostly expressed that I feel very responsible for the output of my work. As an IC, that output entails my own code, reviews, productivity, planning, comms, etc. As an IC, I am comfortable taking on and driving high-stakes projects and taking responsibility for them. It can get stressful (as rushing to a release deadline in that industry usually is), but it's always been "good stress".
But as a team lead, I felt responsible for the planning and output of others on the team and the team as a whole. Making sure they have everything they need for success, _their_ output along with my own, how others' time management fits into our deliveries, the quality of their code as well as my own, what tools and support they need, etc. I think some people thrive in that situation, but for me it culminated in a bad kind of stress. And I just didn't think I could do the position justice like someone who genuinely enjoyed that side of it.
The other part of it was that I felt like my time to grow as a programmer was diminished by the extra planning meetings, more ticket management, 1-1s, etc.
They were a little disappointed at first; from what I understand they thought I was doing a good job. But they were supportive nonetheless. I still got promoted (on the IC track) in my end of year review so it worked out.
From what I understand it doesn't always go so smoothly. I've heard of some places where trying to move back to IC ends up in practice being treated as a sort of demotion (or at least stagnation?). Luckily this was not the case where I worked at the time. The company had a documented job matrix of engineering career progression along IC, TD, and Management tracks.