Imagine your brain as a snowy hill. Each decision you make is like sledding down the hill, causing a slight indentation in the snow. The more times you make a decision, the deeper the groove, the faster you make the decision and the harder it is to try something different and escape the groove. Psychedelics is like fresh powder on the hill won't the grooves away so you can try new ways of thinking / new routes down the hill.
I will add this: the shape of the hill stays the same, and mostly that fresh powder will melt back into those old ruts... the changes that these experiences bring seem, to me, more about knowing the ruts are there then they are about changing things in our lives.
The change comes from the awareness of what can be done, because formerly "natural" things that are "just what people do" start to seem like artificial, learned behaviors. That's a powerful thing to grok, and easier to comprehend at the level of our nervous system with these substances.
I haven't found these drugs to be super "fun" outside of the non-recreational ways of doing things, but the older I get the more I enjoy things that most folks find exceptionally boring. But I do find them very useful.
For people who people worry about the long term effects of these things; I feel like for most healthy adults, if they "start small" the actual long-lasting effects are pretty minor.
Here's an idea to consider for curious folks: if one or two psychedelic experiences could fundamentally alter your views on your life, you probably ought to consider the deep things in your life more often.
the long lasting effects were negligible for me. the biggest change was that i realized i might be "on the spectrum" but it isn't as though it was a life-changing realization.
i agree regarding your final point. i do think that psychedelics are more "helpful" for people who are extremely extraverted or otherwise reluctant to reflect on themselves.
I wish that I had not had to see out how badly my drinking impacted my marriage with my second wife when she unexpectedly left me, but it was a thing that I needed to learn.
So I take your point, and I am glad to learn things. In general I find learning an enjoyable experience. There are a certain amount of life-altering, important facts about ourselves that are painful to encounter in any situation.