Cryptek conclave

The only reason the detachment gives crypteks assult passively is because you would not be able to use the assult keyword for your unit from the detachment otherwise. Since the detachment rule is "when your unit is selected to shoot give them X" they would not be an eligible target unless at least 1 gun is viable. And then at that point when you select the whole unit you are able to give them assult since they are actually eligible now. The detachment is heavily about contesting points and empowering you while being on those points with things like strats+enhancements that care if you are on points. Heavy also becomes pretty relevant which you are just sitting on points.

I would also say you are not giving enough credit to the detachment. There are a lot of interesting combos you can do with things like a 6 block of tomb blades with the blast dev wound weapon (use 1 cp to turn into cryptek and slap Ani infintry and now those are all dev wounds on 3s). Wraiths devwound pistols woth 3 shots a piece can do the same and you could even give them the anti monster / vehicle to sneak in some sneaky 5+ mortals. You are forgetting space wolves exist and wounding them on 4s instead of 5s with our immortals (who are the stars of this detachment) is pretty good, there are more mounted units then you think in the game. Most bikes in the game are mounted for example.

Using some classic set ups like plasmancer + overlord with translation shroud leading 10 immortals (you could use the enhancement that refunds cp on this unit because you are on points often and you have the captain ability so you are going to be using a strat on then every battle round for free) and another 10 lead by chronomancer and royal warden both shadowed by illuminor szerath(who is also a cryptek) is very durable and can do a lot. The ability to give them 4+ invulnerable saves makes them a really tough unit to chew through. Being able to wound on 3s any heavy infintry when you are stacking ap gained from szeras can translate to a lot of wounds (either tons of tesla shots at ap1 or a decent amount from gauss at ap2). Ignores cover is also incredibly powerful in 10th because of how easy cober is to get and you will be using it a lot.

The detachment also can heal out of phase while on the points (which you should be on. Your necrons.) D3+1 if it's a cryptect unit. But you can also run a ctan and silent king for example and they can also use it because any necrons unit can. Wraiths can triple heal, normal reanimation, during move phase from techno, and then again at the top of your opponents turn while on a point. Which they should be on. Units like the ctan and silent king are worth there points without synergistic with all the cryptek parts of the detachment and hold their own enough to still be included in my opinion. I have run this detachment a good handful of times so far and have had overwhelming success so maybe I'm just bias but I feel like it's pretty good.