Ironically, I think existing DMs going on endlessly about how hard it is is part of the problem. It isn't hard. We did it at 10 years old. Almost anyone can do it. Certainly one of the five of you can do it.
I don't think DM'ing is hard. I do think DM'ing WELL is hard.
I also don't think we DM'd well at 10 years old. Of course, our 10-year old peers didn't have a high bar of expectations for us to meet, either.
To say nothing of the fact that if I recall correctly the average "new game" skews older (college age?) now than when I got started (I was in the single digits at the time but I think most new players were tweens) and generally we have higher expectations for how we use our leisure time at, say 20 years old than we do at 10 years old... 10-year-olds generally tolerate lower-quality entertainment than 20-year olds (if, for no other reason, because they have less experience with entertainment and thus less to compare it to).
However, let's be honest about the expectations of the minimum material that needs to be digested prior to running your first game.
If you came in as a BECMI player, there were at most 112 pages of rules for you to get through to get started (64 pages in the Mentzger Basic Player's Guide, 48 in the DM's Guide, which included the monsters; the Moldvay Basic rules were even shorter). Even if you slot in the Expert rulebook as required reading, you have 14 levels of play across less than 200 pages.
For 1e AD&D, the PHB (128 page), DMG (236 pages), and MM (112 pages)
combined for 476 pages. That's a significant amount of reading but those books are somewhat eye-friendly with a lot of white space (especially the MM) and tables (the DMG) so text density was low.
Contrast this with 5e where the PHB (316 pages), DMG (320 pages), and MM (352 pages) are nigh on a thousand pages (976 to be exact) of nicely illustrated but very dense text - white space is gone. Without even accounting for text density, that's more than double the old 1e required reading and about nine times the required reading of the old Basic Set!
Most of this is because there are simply MORE RULES in 5e than in BECMI or 1e (admittedly, they're more unified now; I don't expect BECMI or 1e players to know a 7th-level Thief's percentile chance to Hide in Shadows; I expect them to look at a table). We, the older generation of games, seem to want more things concretely outlined in the rules which leads to less ambiguity but also more rules complexity.
I happen to think despite complaints about "shorter attention spans" and "less literacy in general" in today's generation (whether or not you believe or agree with these sentiments), 100 pages of reading to get into a hobby is something you can still ask of a reasonably intelligent 10-year old. But 5e requires the aspiring DM to wade through
an order of magnitude more reading before you can try to get started!
In short, whether we want to admit it or not, the "bar" for a "new DM" has been raised from where it was when we were young.
Last week I ran the Pathfinder Beginner Box with a group of mostly new players (all new to PF, one was a player in a 5e campaign I previously ran), all in their 20's. They all seemed to enjoy the experience but only one player even cracked open the 76-page Heroes Handbook. I think 76 pages is close to the 64 pages of the old Basic Player's Guide, but apparently the text density was too intimidating for most of the group! Most of them were quite happy with the 4-page-equivalent pregenerated character pamphlets (well, since one was a pretty cover page, effectively 3-pages, with rules summaries for spells, et al on them).
That to me suggests even the least-intimidating introductory products currently on the market are overstuffed with content and intimidating to new players. New players are happy with a bare minimum (3 pages?) of rules. I would theorize that 5e, PF, and their ilk are carrying far too much rules bloat to be all that accessible to new players, much less new DMs. That's why new players often want an experienced hand to guide them... I think the amount of stuff in RPGs now is too overwhelming for a player, who is only worrying about one character, to comprehend it without some help and trying to understand all aspects of a game would be simply impossible. Lots of crunchy stuff may be satisfying for experienced gamers that have had years (nay, decades) of experience layering on more and more rules, but from what I've observed, it creates a huge barrier to entry to those that lack the same experience.