If you can grab the Uber Sword of Doom when the monster is 30 times stronger than you at level 1, you earned it.
Get your head around the idea that level scaling is the problem. As long as the treasure is given the equivalent difficulty obstacle, there is no exploit. It is only when you magically make every monster level 1 in order to scale with a weak player, that you cause the problem to begin with.
I don't know any old school RPG that turns a supposed ultimate weapon of doom into a pathetic toothpick just because you got the quest at level 1.
I agree the scaling that accompanies so many aspects of the past games made more problems than it solved. I can see how making enemies and weapons slide slightly up in performance is advantageous to the game play staying challenging, but there are smarter ways to do it. Unique items should have static attributes so no matter when you find them (early or late) in the game they are what they are without deviation. Some scaling can help, but there shoudl be cut offs so thinsg do not become ridiculous.
In the case of enemies their stats should slide with your through the game but should slide only a few levels before being replaced with a legitimately more powerful enemy to fight. Thus, as you progress through the game roadside thieves should stop appearing and in their place gangs of mercenaries should appear which in time are replaced with notorious "opposite aligned” adventures who would be your natural enemy. Thus you never meet a solitary thief with powerful armor, but would meet a high-level adventures with some back-story who do not like you or thinks stealing from you is their next adventure.
In the case of weapons they increase but only in chest you have not opened as much and mostly deep within well-protected tombs, crypts, or ruins. Low-level trash still appears in the easier to get to areas and some randomness is allowed so that good finds are possible without traveling too deep, but the best way to give out good items is to have them behind enemies you need enough skill to defeat to EARN the items.