You should be able to purchase a socket for 1000 valor, 500 conquest, or (whatever amount is appropriate) Stygian embers with no reputation requirement for anybody!
That you can only get sockets from one place is absurd. You’re telling me that only one guy can put a hole in your armor and the only thing he wants are 1000 soul cinders?
If something is relevant somwhere, you should be able to get them in that place. And sockets are relevant in dungeons, PvP, and raid!
My thing with gear in general is “do all this grinding for one character but you can’t do everything on that one character… oh you want to play an alt? haha you’re funny.” Then things are touted as “alt friendly” when they are fixed, but often times they aren’t and they should have been alt friendly in the first place!
You can also get sockets for 5000 catalogued research I think
I agree with OP. Having thousands of unspent conquest because I literally bought every piece of gear for DH for mog purposes and geared all my alts through conquest chests. Why not give PvPers a way to get sockets other than PVE means?
As well as pvers a way to get sockets sockets other than boring pve means 
amen to that brother!
I think it would be better to argue that Sockets should just already be on every piece of gear that we can place said sockets on.
Personally I think several of the tertiary stats are largely harmless and don’t do much of anything but add flavor to an item. Sockets are a bit of a different story. Even in a small amount they do impact player power and having them creates some of the interconnections we came to expect from WoW before itemization was largely changed between MoP and BFA. Back in WoD they started to downsize the amount of changed and additions you needed to make to a piece of gear before equipping it. This convenience change never quite came to fruition with BFA having some items that were item level upgrades but not better due to secondary stat weights and combos with Azerite powers. Now that Azerite gear is gone and so is titanforging along with better main stat to AP/SP values.
I think making it so epic and legendary items in specific slots (Helm, Neck, Bracers, Belt, Ring) always have a socket would be a welcome change to add more consistency among gear and remove some of the carrot on a stick design with random socket upgrades and socket upgrade items.
I think SL and by extension WoW has done quite enough of the moving goal posts over the past 6 years. Gear will always be the primary example of this and that is fine but having these extra minor goal posts generally feel like unnecessary padding to get players to engage in content they might not want to.
Oh dang yeah this would be the best option of them all, or maybe even get rid of sockets, any of the above will work for me 
Shadowlands in one sentence lol
Having to gather old siege of org gear and gems did make me miss how awesome pieces of gear looked with all the gems and enchants on it. Definitely wish all gear enchants and gems come back in the future.
In movies, it’s “Location, location, location.”
In games, it’s “Content, content, content.”
Sadly, Blizzard has yet to realize this fact.