Yaarel
🇮🇱 🇺🇦 He-Mage
Wait, your rationale, "keep it simple", is why WotC should never introduce magic items in the first place.The only way you will understand why this isn't necessarily best for the game (read "WotC's coffers") is when you stop underestimating how the introduction of such advice will impact people's impression of D&D as a complicated and difficult game.
WotC just isn't interested in delving the deeps of this complex question. They (hopefully*) realize that any such system needs to be quite involved to be worth a damn; and they simply don't want the general public to see such stuff anywhere in the PHB or the DMG.
*) I would be sad if they actually believe the shite system where you essentially randomize magic item prices is useful
And if magic items are defacto default, then they need to become available in a way that is mechanically balanced, safe, and incremental.
The DM needs to understand how to manage magic items to actively avoid destroying the game.
Otherwise. Forget magic items. Just reskin feats and call it an item. So simple.