You might like Requiem. It definitely rewards preparation. Since the world does not change, more and more enemies fall within the players capability as the character gains experience and levels. But because of the way combat works (with such high damage output and armor piercing weapons), even lowly bandits can kill a fairly high level character if they are not careful. On the other hand, with enough preparation, it is possible (but by no means easy -- you need well-smithed daedric) to get your AR high enough (you need about 1,500 AR) to easily withstand even armor piercing attacks. At that point, you can start to safely take on dragons in melee. Characters who have light armor or lesser heavy armor can try to take dragons in melee, but an unblocked melee hit by a dragon is going to mean instant death for most characters with less than 1,200 to 1,500 AR, so your block skill will tested. Most characters opt to deal with dragons at range.
All of the high level enemies require a lot of preparation, and in some cases particular types of weaponry or magic to defeat. Spriggans, for instance can't be killed with unenchanted swords or hammers. You need axes, or a weapon enchanted with fire damage. A fire enchanted axe will cut through them like butter. An unenchanted axe will kill them but only if you can overcome their regeneration with enough DPS, so you need a really good axe and enough skill/perks in axes. Or you can hold a torch in one hand and alternate between bashing with the torch (to temporarily stop the regen) and swinging with the axe. There are probably many other ways to kill spriggans, but charging in and hitting them with an unenchanted sword or hammer is just going to get you killed even if you have a fairly high level character.
Earlier you asked about getting one shotted at high level. Once your character is powerful enough, there is very little that can one shot kill you (but giant slaughterfish can swallow you whole and kill you in one gulp no matter who you are -- so be careful swimming in deep dark places where those lurk -- or kill them from shore first).
Requiem has a slider in its MCM menu that lets you adjust the maximum percent of resistances for things like magic resistance or damage resistance. Default is 90% but you can move it up or down to suit your tastes. But at 90%, your best armor will give you twice the protection of the 80% vanilla damage resistance. So, even though the high level Requiem enemies are doing twice as much damage as vanilla Legendary, you can still survive being hit if you get your armor skill/perks and get good enough gear. But it takes a lot of work to get there, since pretty much the only way to get daedra hearts in Requiem is to kill dremora and they are rare and hard to kill. You also can't just learn daedric smithing by merely grinding your skill, you also need to find a particular book to learn the secrets and unlock that perk and the book is well guarded.
Since there is so much stuff in Requiem that can kill you so quickly, DiD play is very challenging. But not impossible. I have talked on line with people who play DiD with Requiem and it can be done. And one thing about the unleveled world is that you can eventually outlevel your enemies. The longer you survive the more powerful you become, and if you survive long enough, you can become very very powerful. With enough AR and magic resistance, nothing can one shot kill you. You might just really enjoy it, since we both like a style of play where your character has to work their way up in the world.