Where did the assasians go?

Is it just me, or are assassians becoming irrelevant in league as a whole? When bruicers became the big thing, assasians fell behind as the bruicers had the same dmg, but introduced good cc aswell as tank stats. Their dmg was also AOE, assassians became useless compaired to a riven mid for instance. However riot fixed that problem by buffing up the assassians to a godlike level. After a few adjustments the game felt balanced. Assiasians killed mages and adcs, adcs killed off bruicers, and bruicers dealt with the assiasians.

Recently we have seen a spike in mages like cass, that can straight outdamage anything that comes in their path, they deal more dmg than assasians, have better cc than bruicers, have better aoe than bruicers, better sustain than anyone. When the game has so many champs that can straightout outdamage every assassian while offering more at the table, the assassian role is going to die out, like how it has been for the end of the season. The only assasians that stay relevant, are the aassians in the jungle, that doesnt get punished by their laning phase against a mage.

I know how frusterating for an ADC to get one-shot by an assassian is, but in the current state of the game, adcs can almost freeroam without worrying of an assassian lurking in the shadows, instead they are worrying about dodging all the skillshots an ahri, zoe or neeko can throw out. What do you think is more frustrating; an assassian who lands his whole flashy combo, and kills you. You look back and think about how you could have outplayed him. Or a zoe that that lands a single spell from the fog of war that oneshots you.

Should the assassian-role stay relevant in the future? If so, how can we save it?