The biggest issue with Professions right now is that most of them become utterly useless late game, and bring nothing to the table with the exception of Alch and Enchanting.
My suggestion would be to break down the professions and make them more about enhancements rather than gear, for example.
Accessories Specialist - Leatherworking can already makes drums of war, but that is meh, as they are almost never needed except in 5 mans. but why can they not make other accessories for raids/dungeon groups? For Example A mound of Hides that can be placed on the ground and gives groups a 5% damage reduction buff if they click on it, like the random ones that LWer’s can find throughout BFA, or something that can Bind a player or NPC like a hogtie, giving more classes the opportunity to get another CC if they lack them, Hell, bring back Saddles to allow more than one person to get on your mount.
Weapon Specialist - Leatherworkers should be-able to make different types of Hilts that can add to weapon speed, or other unique properties that enchanting can not do! Letting you chose between the two professions, or if you have two weapons use both.
Armor Specialist - Items that allow you to add sockets to leather or mail pieces, or you can make patches to improve durability mid fight (can work on weapons as well) so if a weapon or piece of armor breaks mid fight and you get Battled ressed, you now have a way of repairing that piece to continue the fight.
Or worse comes to worse, have bosses drop pieces of the current expansion and allow the profession makes to stick those pieces into a tier set piece or something.
I think what it comes down to is the devs don’t want to deal with such enhancements cause they will have to do more number crunching for gear and instance mobs/boss fights.
Look at what enchanting was before and is now. A gutted profession that’s almost totally useless.
I’d be happy with just being able to upgrade gear.
Remember that green quest axe you got? Well for x ore and x flux you can upgrade it to a blue axe.
Make the cost reletive to the ilvl upgrade or something. Plus make it something you can do for other people like enchanting.
I will say though, I have no clue how to make inscription and jewel crafting relevant again. Maybe give inscription real shoulder enchants or something.