Yay! Well, if we take Elden Ring as an example, I'm a massive fan, especially of its open world. It offers an unparalleled opportunity to simply go almost anywhere you want, which is simply not possible with a more restrictive area layout. What I particularly enjoyed is that you can go to what you see in the distance and there is much to see in the distance (Elden Ring offers great view points). Sure in previous Souls titles you saw a bit texture of familiar architecture in front of the skybox but Elden Ring you not only see Raya Lucaria in the distance but also the path you traverse to get there with ruins and towers on the side and from the academy you the see the Three Sister and from there an even better look at Ranni's estate etc.
I find both the locations you find strewn about in the open world as well as the enemy encounters varied enough. Group enemny encounters are quite decently designed in Elden Ring: Even if you agro the whole camp, you aren't getting mobbed by a dozen enemies like if you aggroed half the dungeon in DS2. Here you only get engaged by 3-4 enemies while the rest stand around waiting for their turn like action movie extras. The only thing that gets a bit repetitive are the standard catacombs textures and layouts (even though I quite enjoy some of them). This improves significantly in the DLC, where there are only three catacombs, each with a unique gimmick. Using minor dungeons to connect to new areas is also something I enjoy. Ruin-Strewn Precipice is one of the four (!) ways to the Altus Plateau and Darklight Catacombs is the way to the Abyssal Woods. I wish there was a different way to the Abyssal Woods, but my mind was blown the first time I exited the dungeon. Interacting with (Legacy) Dungeons from the overworld is under utilized in Elden Ring in my opinion. I thoroughly enjoyed the way you could access different parts of Castle Ensis from Scadu Altus. Imagine if you could access different part of Limgrave or even Liurnia from Strom Veil Castle.
The most exciting part, for me, about the open world of Elden Ring is actually not the first playthrough, but the nigh unrivaled replayability that it offers. Let me explain: On first playthrough the best thing you get from an encounter might simply be the Runes, but on a subsequent playthrough you already know where everything is and with the unparalled access that the open world provides to everything you can uniquely route each playthrough. But all of this only works because area traversal is so fast in Elden Ring. The Trarnished doesn't get exhausted after like three steps like the Cursed One and what people don't seem to realize is how incerdibly fast Torrent actually is. On a first playthrough where you stop for every interesting bauble and sight you don't notice it, but incredibly long journeys like Bestial Sanctum to Redmane Castle go by incredible fast on the back of our awesome spectral steed. Another aspect are the trapped chests, sending gates, quests, and myriad other things that shortcut the world. The Routing possiblities are endless making every playthrough of Elden Ring unique.