One of the mains reasons has to do with a quality of mind that is open to ideas outside of the worldview and presuppositions that surround all of us in mainstream culture. It is a willingness essentially to not care what others think, and therefore to pursue the truth wherever it leads regardless of peer pressure, family pressure, social standing etc.
In it's heyday, the constellation of issues and areas that were of concern to the "Dissident Right" writ large was extremely wide and broad. It extended from everything to diet, exercise, man-woman relations, race, JQ, etc. And if you were able to "break through" on one or more issues, it eventually became a habit of mind to focus on objective truth regardless of how much of a threat such a search might be to one's longstanding worldview, one's social group, one's identity, etc.
To give a petty but very real example, many people (myself included) were raised to believe that cholesterol and saturated fat were extremely unhealthy and even dangerous. The only way to find out the reality of their healthful properties was an independence of mind, a natural curiosity and propensity to research, a willingness to consider non-mainstream sources and an open-mindedness and willingness to reject "common knowledge" and ultimately a willingness to act against what every fiber of your being was telling you not to do.
Once that process has played out on, say, cholesterol and saturated fat, you move on to cardio vs. weights, and maybe this leads to research on male and female roles, etc. The same thing can play out in the areas of crime and race and the JQ etc. This process I am describing was a very real thing, particularly back in the "early days" of the dissident right (say 2009-2014), when you really had to piece through it issue by issue and search these things out.
I think the same willingness to "abandon one's identify", if you will, in those many areas, left people with a habit of mind that was willing to abandon something even as deep and entrenched as one's default religious identity, in part because of a realization that one's acceptance of the original worldview was never based upon any consideration of its merits. If your identity and habits are now about Truth Seeking above all else, you will simply view the options in a more disinterested and objective way. The fact is that this type of disinterested and sincere search will in many cases lead to Orthodoxy.
The fact that many people today in the West also lack a solid core identity may also make that process easier and even necessary for some: You have to seek out and claim your identity, since many of the standard types of identity other cultures take for granted have been diluted, stolen, abandoned.
If this all sounds a bit triumphalist about Orthodoxy, so be it. The fact is, from my perspective, Orthodoxy does get closer to the Truth than any alternative.
To sum this up a different way, the qualities of mind that made many people open to the Red Pill also made them open to the God Pill, and very specifically to the Orthodox Pill.
