Thank you! I didn't know anything about working with bare metal when I started out, and relied on the OSDev Wiki and other online resources. The work of those early years isn't as mature as now, but I learned a lot. Later on, I graduated to being comfortable reading (for example) the CPU manuals, and realised that I could now really get value out of them! Overall, I feel a lot more comfortable in the domain and like I can tackle a new device driver, or set off making the hardware do something obtuse and wrangle it out, but I only got there through trying to do it with less expertise under my belt.
There's definitely a bootstrapping problem with the lower-level knowledge, but there are enough resources out there for the initial steps that anyone can get started, and you can do a lot if you enjoy the journey!