There should be an option that indicates the current drop rate is fair enough.
I don't think there's anything inherently unfair about any drop rate. It would only be unfair if we were misled about how common the drops would be. We knew early on it these were rare and a would be a tough grind for a lot of players.
There are plenty of items in the game I would like to have, but don't because I don't want to do what is necessary to obtain them. In none of those cases do I think it's unfair. I don't think this is any different. I don't think that in a game like this players should ever feel entitled to an item.
I am legitimately surprised so many people are completely obsessed over 4 cosmetic items and would do something so agonizing to them to get them.
I didn't enjoy any of the activities, but I found ways to make them fun for me and I appreciated that I was encouraged to engage with other players in the community I wouldn't have otherwise engaged with. It was fun to see so many players excited to get their drops. Ironically, it was also fun to see so many interesting outfits.
I found the rewards very good when the gift boxes are considered: millions of gold worth of mats, motifs and recipes. The icing cake is 4 items I'll fondly remember getting after some effort and determination.
As one of the unlucky ones who stopped counting after 500 Vvardenfell world bosses the issue is not whether 1% or 0.1% or whatever is fair but adding an overall counter that at a certain point guarantees the drop.
RNG will always be RNG; Some folks will get lucky, some will sit at the median but there will always be those who are stuck at the very outer edge and worse being RNG there are those who will simply never be able to get that drop no matter how long they grind.
If adding a total counter is considered too much overhead then any drop chance below 5% is straight up too low for anything, end of discussion.
As for the current events style pages nothing will convince me that the drops aren't actually bugged in some way. My guess is they screwed up the Vvardenfell boss drop whereby each time you have a 0.0001% chance to get a style page but once you pass that check it's further RNG as to which style page and if you already got one of them and it rerolls that same page you get nothing.