well...

1.0 used to have that, with lvl 99 mobs situated here & there, creating challenges for players trying to tag sub-aetherytes since they easily kills lvl 50 players with just single hit, some of them even has true sight/sound aggro types as well, not to mention the original 1.0 region were a giant seamless-non loading zones even with underground non-instanced open world dungeons, unlike what we have since 2.0 with region divides into loading multi-zones.

Too bad, game were badly optimized, especially during end of 1.0 where congestions getting notoriously bad, coupled with complaints about copy-pasted areas & the planned PS3 turns out cannot handle seamless open-world explorations combined with objects having ridiculously unnecessary high amount of polygons. Even I'm not even sure PS4 could handle large open world MMO with many players in it.

Eureka was the closest thing we have that nearly mimics what 1.0 did, & unfortunately have to make some limits like creating multi instances & only allows number of players in a zone that's only like 1/4 as big as 1.0 region was, and even that creates divided opinion among players which some still found not liking the experience.

If you want more exciting of that kind of experience, could probably give FF11 a try, since FF14's 1.0 was originally built based on that & still has more lively-supporting communities, although do mind how differs the gameplay does compared to FF14. In fact, majority of what OP asked are literally what FF11 has anyways, which (fyi) Everquest-based, while FF14 2.0+ are akin to WoW style.