Crafting magical items should involve spell components just like spells do. These spell components should come from various creatures you meet, defeat and use.
For example, a frost themed blade could be required to be forged on the winter solstice, enchanted with an absorption spell, then used to absorb the breath of a white dragon.
This information should be with the item in the DMG, or various parts of monsters should be mentioned as being good for crafting magical items and potions in the monster manual.
This would make it difficult for PC's to just craft any magical item that they wanted, but would still make the crafting of magical items be a possibility for PC's. They would just have to choose the magical items they really wanted and quest for them.
I once had a DM who made all crafted magical items come at a penalty and a material cost instead of an XP cost. My ranger's frost bow had to be coated with white dragon blood. The Coating process have him unremovable cold vulnerability FOR A YEAR . Because of this, PCs and NPCs "almost" never sold their items or had to take long chunks of their adventuring lives off until their crafting injuries wore off. This also had three other side effects: few consumable items were ever crafted, everybody and their mama hunted people who had magic items to bypass crafting injuries, and magic merchants few and far between due to the rarity of magic items and the constant hounding of robbers.
I want to see magical items craftable by PCs but gold and XP costs were lame. And time costs are too limiting. I hope for some other cost for magic though.