Wow, there is so much information in this thread. I previously thought I understood, but now I suspect I have a knowledge gap regarding security of my accounts. I will need to reread this thread again several times and consider changing my strategy. I would very much prefer for it to be relatively simple to address these issues.
I have felt pretty secure with my single Internet Identity, multiple devices (iPhone, iPad, windows hello, 2x yubikey), and backup seed phrase. I do know that anyone with access to any one of my devices can add their device, delete my devices, and delete my recovery method. Knowing this, I also had the attitude of “not your keys, not your crypto” in regards to maintaining access to these devices. In other words, I absolutely must keep the devices protected, locked, and only accessible by me (except leaving explicit instructions for my family in case something happens to me).
While I still think the “not your keys, not your crypto” mantra applies to a large extent, this is probably an oversimplification. I have much to learn. There are so many concepts in this thread that are not familiar to me at this time.
Again, I would prefer a much simpler method of making sure others cannot take over my internet identity and accounts. I support identification and implementation of better recovery methods.
@Roman please note that I edited this post so hopefully it better explains what I was trying to say.