These were previously Cursed Charms, which were admittedly pretty easy to work around. Which in turn spawned the idea of Cursed Crowns instead.
On paper, these do add a challenging element with a bit of freedom. For example, the Glass Crown (-2 HP) isn't forced onto any companion. You get to decide if you want to use it, at the cost of -2 HP.
The biggest issue is a lot of these Cursed Crowns cannot be placed on non-companion cards. A very fun part of this game is Crown combos, finding a strategy that's good and putting the pieces together to enact it.
Unsure how I feel about them being non-removable. It is a difficult restriction, which goes in hand with the Bell system. But at the same time it forces you to commit to a card/companion very early on, which can feel lame at times.
Preferably, these Cursed Crowns should be able to be placed on non-companion cards. Perhaps they can have two effects, one that affects companions only and one that affects other cards only.