Why not make new cards devotion?

I mean, we all know that all these new cards are too OP and are / will be breaking the game balance.
Considering they are all linked to deities / religion, shouldn't it be obvious that they shall be limited to "devotion" decks?

That would require players to constrain themselves when building decks around these powerful cards, and be very rewarding for them to do so. On the other hand, if you want to have you oneiro/renfri/GN/squirell/Heatwave/[name any OP neutral card], then you can do so but you cannot get the value of these new cards.

Finally, that would actually be a good way to give more importance to this keyword, which is very limited to Symbiosis / SY these days i reckon…

By the way that would not be so constraining for players :
ST = Harmony can easily be devotion
SY = Firesworn can easily be devotion
SK = warriors can easily be devotion
MO = DW can easily be devotion
NG = Assimilate/spy/status can easily be devotion
Etc.

What do you think ?