In 5e, magic items are handled in a rather weird fashion, with Xanathar's offering a bolt on market system for magic items and the scaling for items being distinctly odd. This system also offered attunement for items, with limited slots and, seriously weird crafting rules. 5e also brought a change from the highest limits being +5 bonuses to the highest limit being +3 bonuses. Compare that to 3e/3.5e (hereafter 3e). In both of these feats offered PCs a tool to create magic items for themselves, although it would mostly be NPCs, and every item had a carefully calculated price. What I'm proposing is that 6e brings through, with suitable changes, is a version of those 3e crafting rules from the start. If you want a +3 Holy Avenger, that will have a price, and that price will determine how long it takes to craft. However, I'm going to take a couple of things from 5e. I have no problem with the top end bonus being limited to +3. You can, as you will know if you're familiar ...
This blog is written with the assumption that Wizards of the Coast lose their marbles and appoint me to be the lead designer for 6e D&D! It's not going to start as a serious play-test build, more outlining the ideas I'd like to see but if there is enough interest it might build up to more.