I mean, depends on what information you're trying to conceal. I'm used to playing card games where my opponents don't get to know my cards. My partners don't either, but based on playing with me a lot, they can figure out what situations I'm likely to do what in. My gameplay changes a lot based on the score, and it also changes a lot based on how I read my opponents. Now, there are a couple people I've played enough with and talked to about my reasoning enough that they know how I'm going to react to these different situations reasonably well. But it's a lot of feel, and it's going to be difficult to draft up on a card. Furthermore, the big thing is that I'd have to explain what I think my partner means by his bids to my opponents. Like, I know his subtleties, so I know that at this point of the game, he's much more likely to be bluffing, or he's playing more aggressively, or he's now calling for me to do X. But, I really don't see why I should have to tell you that. And maybe that means I don't want to play bridge. But what I'm describing is also not 'degenerate', as you say.
You are talking as if bridge players had not considered this. I am fairly sure this is how bridge was played in the old days, and it was a much less interesting game.
Of course, you are also missing how subtle partnership communication in bridge is. There is still a lot of advantage for you to know your partner's tendencies, since (in the bidding) it's more important for you to know partner's cards than for your opponents. Nevertheless, you have to keep a balance between giving a lot of information during the bidding (to allow partner to place the right contract) and concealing your hand (to make finding the right lead or defense more difficult for opponents). On defense there is a lot of skill involved in knowing when it's important for partner to know your cards (signal honestly) or for declarer (signal "dishonestly" or randomly).
In any case, bridge is interesting precisely because you always have some information about the opponents' hands, but typically not enough to be completely sure. That's what makes falsecards possible, or makes the decision whether to go for a technical line, or to hope for a misdefense.
But anyway, these are all technicalities. The main difference is that you play bridge with a partner, and you have to work a lot on your partnership to be on the same wavelength in as many situations as possible.