Uh
If you're captain, you can dedicate one night to Nyzul a week with 5 tags and theoretically get to floor 25 in a single day.
4 weeks = 100 floors
Doesn't really seem like a massive time sink to me. Maybe 3-4 hours of work once a week, but most people already do that in sky, sea, camping, merits..
That'd screw over the people who used their runic discs >_<
Problem is, you're doing it as a Party.
Once you do Floor 100, the persons disc who was used to get there is reset, and is given another key item that lets them(and THEM ONLY,) redo floors without the use of a disc. You'd need to go 0-100 6 times to equip everyone in the static with these keys, and hope you don't have to get replacements for people who quit. Even at a complete 100% win rate, you're looking at 35 floors a week. Potentially more if you're lucky. But 35 is still pretty optimistic. That'd take over 17 weeks, at 100% clear rate, to get all 6 people set up with Runic Keys. 17 weeks at the minimum just to have the ability to do 7 floor 100s a week.
Now, not only that, but the weapon you want has to drop as well. So you'll have to fight the 1/20 odds as well, and deal with repeat drops on things you do not want.
As for tokens and people who use their discs getting screwed over, simply put, for a group of 6 to all go 0-100 6 times, you're going to sit on a ton of tokens. I don't know how many tokens non-disc holders in my group have, even with using my disc for the last 6 months a majority of the time, I still have just under 30k. And thats with floor transfers, a spy's drink, and a fanatic's drink being purchased every entry. They're probably pushing almost 100k easy.
Aside from money and playing the waiting game, a Dynamis relic weapon can be completed in as little as 6 or 7 runs I think. Assuming everything goes that one persons way. So you'd be looking at about 3 weeks for the actual Dynamis portion of that if you ran as soon as you could every time and have a horseshoe up your ass.
Fortunantly, unlike Nyzul, if things don't exactly go your way in Dynamis, the odds of getting the drops you need is significantly better than that of Nyzuls, since attestations are divided among multiple NMs instead of thrown on just one. 1 in 3 > 1 in 20.
Bare minimum, they're pretty much equal time requirements as far as actual work goes.