I feel like a lot of folks are glossing over the requirements to craft a magic item. If I understood the previews right, you need three things: an Arcana skill proficiency, the appropriate Artisan Tool proficiency for the item type, and the appropriate spell prepared for the specific item. And each participating crafter needs all three individually, not collectively.
Which means that maybe a Human Wizard with the Artisan Background and Skilled as their bonus Origin feat who was specifically designed to be an omni-crafter could make most of the items in the book. Assuredly there will be some items that require non-Wizard spells, after all. But you average PC caster? One that's not using Custom Backgrounds?
You average PC might grab Arcana proficiency, and they might make an effort to get one or two Artisan Tool proficiencies. But they don't have the Tool proficiency for a lot of items. They don't have the right spells available for a lot of items, especially if they're not a caster than can freely swap their spells out.
So I don't expect most parties to suddenly be self-sufficient with these rules. It's something that will fill a few gaps and be a possible use for downtime and gold. But a lot of time they'll still need to loot, purchase, or commission what they really want. And hey, these rules double a great template for commissioning NPCs to make what you want.