Unfortunately bitcoin self custody is complex and easy to mess up, even for seasoned bitcoiners (look at Luke Jr). It's not as simple as just memorizing 12 words. First of all, memorizing your seed is a horrible idea. Please don't do that. You will forget it! Second, it's where and how you store them, how you use them, how you transport them if needed. There are many variables. OPs mention of custody inducing anxiety is relevant. One mistake can cost you everything, and when it comes to self custody mistakes are simple to make. That can be motivation for education, but not everyone is built like that.

Self custody has to be backed by understanding of risk and the ability to take ownership and responsibility, which are characteristics of a mature individual. Most people are ignorant, they seek comfort and rely on custodial trust without understanding its implications, and not even caring about them. If you're not already inclined towards sovereignty, the biggest pro self custody lesson is to get burned badly by the custodian system, and then having the willingness to educate yourself on better alternatives.

This is a hard point to grasp but in some cases it's probably not even recommended. It's just too complicated for some people. Old people, or people who are not tech savvy, won't be able to store their wealth securely by themselves. The lucky ones will have a knowledgeable good willing family member or close friend help them. To the not so lucky ones I wish them all the best.

There's also the whole KYC problem. We haven't even reached the point where self custody is banned yet. The "then they fight you" phase has barely scratched the surface. What will people do when the government knocks on their door with a 6102 order? Even the simple thought of something like that happening can throw people off. The threat of violence and people being compliant are big reasons why they won't choose self custody.

Nontheless, I think self custody will rise. I also think custodians will never go away. Both will exist.

Self custody is freedom, and freedom comes with responsibility and the need for understanding. Education and willingness to help are keys to a more sovereign society.