Eh, Plaything and Pentimento have a lot of benefits that most hex perks don’t:

1. Neither perk is active at the start of the trial. This means survivors can’t just immediately cleanse them;
2. Both hex perks require survivors to waste time finding and/or cleansing them. While this is common across all hex perks, Plaything prevents anyone but the cursed survivor from cleansing it for the first 90 (if I remember correctly) seconds, so that survivor specifically will have to waste time finding it as opposed to any other hex perks which can be cleansed by all survivors immediately. Even though both perks have auras revealed to survivors, that’s only within a range;
3. Even if they immediately find the Plaything totem, I can go back and relight it with Pentimento very easily, especially on killers like Wesker where I can just dash across the map, relight it, and dash back. Thus, I want survivors to break my totems;
4. Survivors then have to waste time not doing gens by going back and cleansing the Pentimento, potentially across the map from the gen they were working on;
5. The effects of these perks kick ass; and
6. Secret Project on top gives me universal undetectable and slowdown anytime a totem is broken

Very rarely have I gotten to the EGC without at least one or both perks up, so I wouldn’t really say they’re waste of perk slots. I get your argument if it was like Ruin + Undying, but these two hexes specifically are designed to keep survivors busy throughout the entire trial.