Things like these?
This article talks about three of the tools that GMs have available to create a rich and vibrant environment.
www.levelup5e.com
Yes, that sort of thing. I've got some things like that on my own "Interesting Encounters" tables, though not as well developed.
In thinking about the sorts of mid-time frame exploration challenges that would matter for attunement passing, I think I've focused in a bit more today. For attunement to actually prevent the party passing the item around, these things all need to be true:
1. It needs to be something that you can't wait to address--it has to matter now (even though it is longer than combat rounds)
2. It needs to be something where you can address the challenge one character at a time
3. It needs to be something where the challenge actually matters
An example of one that I can think of is an unstable/collapsing area where you need to climb out of it. You aren't in combat rounds, but you can't take all day to do this. Without attunement, you could pass around those
gloves of swimming and climbing or
belt of giant strength to let each character have the bonus to their Strength (Athletics) checks to climb out of it, which is exactly the sort of thing this is designed to prevent.
But many of the sorts of hazards you'll come across are either ones you can take your time on (ie, if you need to climb that cliff and it
isn't collapsing), or ones where everyone has to address it at once (a blizzard or tornado, or other situation where it hits the whole area at once). And if the challenge/hazard/danger isn't really meaningful, then making it easy for the party to overcome it isn't overpowered. In any of those cases, attunement doesn't seem like it should be present, based on the stated criterion.
So I guess the inquiry could turn to whether or not there is the assumption of exposure to sufficient exploration hazards that fit #1-#3 to justify considering that factor for the purpose of attunement rules. I've run hundreds of hours of 5e D&D, and I can't think of many situations (none off the top of my head) where there have been time sensitive challenges outside of combat rounds where item attunement restrictions would make any difference. There have been time-sensitive situations in combat (where passing items is impractical and therefore irrelevent for the passing to the whole party criterion), there has been the Hidden Shrine of Tamoachan where rests damage the whole party (so you can't deal with things one character at a time, again making that attunement criterion irrelevent), and there have been the standard situations where something will happen in a certain number of days, or you need to get to place A within time period B, etc. Again, off the top of my head I can't think of any situations in hundreds of hours of play where #1-#3 all applied in the same situation.
Can anyone else think of any from their campaigns? And are they frequent enough to be worth taking account of for rules restrictions?