Just a bit of anecdote from my personal, recent experience with this content.
Yesterday, I had finished helping 2 friends through 3 of their relics progression via DRn starting from about a couple of weeks ago. So that's exactly 15 DRn ran. Our meet up timing were sporadic, which mean we didn't always catch the server's peak hour.
For the most part we got into the run with just the 3 of us with myself mostly carrying out the weight by doing LAs/Essence swapping as a WHM while they rolled with the basic damage essences and sufficiently helpful actions (mostly to save my cache space by carrying the buffs for me instead). There were like 2 or 3 runs where we would get 1 or 2 stranger who would come along to enjoy the ride, but I also remember exactly 1 of them bailing out after Dahu because apparently it was too long to their comfort. Nevermind that, we pressed on, carrying the burden of an extra missing players and cleared it. And finally there was 1 elusive run where we got paired with another full party of 8 who formed via their own PF and that one run was a total breeze.
Discounting the outliers, most of our 3-man runs took anywhere from 40m to 55m depending on whether we take a few breaks in mid run or I just went on "go go go go!"-mode. Oh yeah, don't forget the 10m queue time too, that also adds up since there's no way we could start the instance undersized until aforementioned timer. Either way, after all these 15 runs helping them, I have say if I were in their shoes without helping hands, it would be very miserable to progress through this specific phase, I wouldn't be so sure if I want to put that load of effort. Doubly so if multiple relics are desired. Ironically enough I did, and still enjoy doing DRn to a lesser degree even today (I wouldn't have cleared all relics while they were current & speedrun PF wasn't even a thing back then if I didn't enjoy them!).
Outside alternative method to farm TAs which I think would be very welcomed to current days' relic grinders (I still wouldn't touch PoTD though!), I would also propose to add the option/check mark to force instance creation just like how Variant Dungeon had shown us in its recent implementation. This would eliminate the mandatory 10m added wasted time per run & remove the possibility of getting paired with folks who just bailed without carrying their own weight, who's also probably unaware that the duty is scaled to the number of players queued into the instance. When these folks bailed, they're essentially forcing the remaining players to carry their weight. This wasn't too noticeable back in the day when 24 player DRn was still common. But in an undersized runs, this hits hard.