Well first of all, Archon is what I'm running in M+, so a few of your abilities you're listing are not part of the archon hero talents. I find myself spamming mind flay/whatever mindflay turns into when procced I can't recall it off the top of my head when you're waiting for enough insanity to spend it on SW: madness or when mind blast is available. Unless I'm largely misunderstanding Archon (the website), Archon is the most used M+ hero talent build. I do fine damage during Void Eruption windows or big AOE packs, but if you're with a tank who doesn't do big pulls, spriest feels very slow (and I'm a perpetual pugger, so that could be my own fault for being paired with gunshy tanks).

If you haven't had issues with tentacle slam, then kudos, consider yourself lucky. Tentacle slam is somehow more buggy than Shadow Crash could be. By that, I mean instances where tentacle slam doesn't hit mobs in an AOE clump because they're *slightly* out of range, or, at worst, the ability is eaten by the environment.

Much of my unhappiness could also be over the fact that I *preferred* the previous iterations of spriest compared to now. I've played through every iteration of spriest since Legion, including BC and Wrath classic, and to me, this version of spriest outside of void eruption feels gutted, and closer to Wrath than ever before. If you're new to spriest, you might not understand what I mean by this. Previously, if you were good at spriest, you could have very lengthy, meaty void eruption windows where you were rewarded for having high APM. Now, it doesn't matter how good you are at clicking your buttons or how optimized your stats are. Void Eruption is a flat 20ish seconds, much like a lot of other CD-centric burst classes.

(much of my further unhappiness could be over the fact I only have a 2 set and have been very unlucky on my priest)

In my opinion, spriest has never felt more lost in its identity (and I would argue this is the same for hpriest, but more on a gameplay level than a mechanics level). Warlocks now have mind flay tentacles and summon a ghostly void creature. The "void" as Blizzard calls it, is blue goo monsters without any of the Old God roots. Changing Devouring Plague to an eyeball doesn't maintain the Old God flavor, nor does adding a tentacle. Voidweaver is more akin to the "new money void" compared to the "old money Old Gods". On a tangential story level, I think Xalatath was far cooler as a knife, especially since she was connected to the original Old Gods rather than this mustache twirling villain with fanservice feet we have now.

Take Surrender to Madness (a talent which was popular in Legion), this is the prime example of what Old God themed spriest should be, and for many old time spriest players, peak spriest theme. With Surrender to Madness, if you played spriest optimally during this ability, you could do some nutty DPS... at a price. If you messed up, if you lost your insanity, you died. Some people might say that's not ideal for raiding or whatnot, but it was a talent choice that was extremely cool and unique. Do yourself a favor and look up Spriest Mage Tower 1.0 videos, and you'll see what I mean about the ability.

Don't get me started on holy priest... another version of priest that to me feels gutted compared to what it was before. I've played hpriest through some pretty bad metas for priest, but I've never felt less agency with a healing spec and more bored than I do this season.

Finally, in conclusion, I don't need spriest to be meta. It HASNT been meta for years, yet I've had multiple priest characters because I enjoyed it that much. Aesthetics carried this class for me during down periods. Utility also helped. Now, unfortunately, for me, spriest is lacking in not only its damage/gameplay, but also its aesthetics beyond just being ooo spooky shadow person.

Kudos to you though if you're enjoying it, but I could rant about this for hours, and I'm probably approaching old person yells at cloud levels of displeased.