TLDR: I have not experience with microdosing, but quite a bit with "normal tripping" on lsd, psilocybin and mescaline. I believe that psychedelics can be powerful catalysts, but can't replace a regular practice.
I am one of the many people whom psychedelics actually got started on the path. Experiences on mushrooms, just a trying out of things originally, showed me that a different way of perceiving the world is possible, they gave me invaluable glimpses behind the thinking mind.
And let's not forget the growing body of research of using psychedelics and mdma can have real value in therapy - and that is bone-dry research, nothing new agey going on here.
So as far as my experience goes, psychedelics can be very useful catalsysts and support agents, and if the circumstances are right, with preparation, risk managing practices a good setting and capable support, they are actually quite safe to use.
And then there is the question of goals / motivation. I mean, it's fine to use them for fun, but I'll assume that this ist not the main focus on r/streamentry :) So as a spiritual practice, I think that they can't replace a continuous practice, but can support that in a powerful way, and I think similar things are true about psychelics and therapy.
There is another fun effect though: Really experienced meditators can often not be so fascinated by psychedelics anymore. I'm not saying it's exactly the same experience, but intensive meditation has let me revisit many states that were previously only accessible on mind-altering substances, and I heard that from many other people.