They are a shortcut to insights, that without, might take a person years to come upon otherwise. And that is if they are actively trying. For most people who aren't normally driven to spend a lot of time actively self-reflecting and critically observing their world with the intent on finding truth, rather than merely confirming their beliefs, psychedelics might be the only way to kickstart things. An important property of psychedelics is that they peel away the ego, which frees one to confront ideas that might normally be too uncomfortable to think about. Of course, psychedelics are not for everyone. Like, it's probably not a good idea for people with, or at risk of developing serious mental illness. And no one should ever feel pressured to take them if they feel uncomfortable about it. But the effects are long lasting-to-permanent with regard to opening one up to seeing the world in new ways, askings questions, and not taking for granted that things are as they seem. So while I agree with you that the idea that everyone should take psychedelics is grandiose, I also agree with OP's sentiment that the world would be a nicer place if more people took them. There's too many people roaming around thinking they've got it all figured out and that there's not much else to the world than what they are familiar with in their own little bubbles. Psychdelics, essentially immediately, pop your bubble and alert you to a much wider plane of existence. It's humbling, while at the same time reassuring, to truly get a sense that we are all connected. And I think it's rare for people to actually experience this without the aid of psychedelics.

I know plenty of close minded people that took psychedelics. I could even argue that psychedelic users tend to be more close minded than the rest of the population —- their religious devotion to these drugs is to me a great example of fundamentalism and rigidness of thought, and the notion that these drugs can be nothing but good betrays arrogance (since insight inherently positions them above the “square” masses that did not take the red pill). I don’t like when religious leaders tell me how I should experience life, and some of the rhetoric by psychedelic users is worryingly similar.

I could also use philosophy to question the very nature of these insights. On what basis does one affirm psychedelic trips provides greater access to reality than regular conscious states?

No one should be telling you that you have to take them, that's as wrong as forcing your religion on somebody. You do you. And as I said, it isn't for everyone.

There's enough research and annecdotal evidence to show that there are indeed positive effects for a lot of people who take them, however.

Certainly, if you're not open to reflecting, you're not going to not going to come to any realization no matter how stoned or sober you are.

And no, I wouldn't say psychedelics get you access to some hidden realty. We all have access to the same thing, they just make it easier to access more of it quicker than if you, say, spent ten years of your life meditating every day. As I said, it's a shortcut, and for some people it can be the kick in the pants that they need to get the ball rolling.

Oh yeah there are lots of evidence showing psychedelics can be useful for sure. I just don’t have much patience for religious zealots, even when they’re part of my own religion.