So Zcash has a huge problem that we are all aware of. Less than 10% of all coins are held within the shielded pool and even fewer transactions have been made fully private (z to z transactions). I believe the last count of fully private transactions was around 10k, and please correct me if I am wrong.
The reason for this is simple. Z addresses suck to use. Sapling is set to fix most of the glaring reasons why, but making z more accessible might not be enough to get people to switch. Exchanges and HODLers care more about profit than privacy. Since this group of people will almost certainly possess most of the coins on the future, we need a way to push them to move their coins into the private pool.
So here is my proposal, do a soft fork that would require all t-to-t transactions to have a minimum 0.01 ZEC fee. Z addresses already have a standard fee of 0.0001 ZEC, so adding this requirement would make doing fully transparent transactions 100x more expensive.
The economic incentive is really clear. Exchanges that process to only t addresses will having higher fees and thus users will be less likely to use them. Investors will move their funds into z address to avoid the larger mining fee, and mobile wallets that pop up will default to generating z address to avoid confusing users on why the fees are so high. And most wallets that DO support t to t will almost certainly put in a pop-up warning telling users that these are more expensive, this making the user less likely to use them at all. By deincentivizing t to t transactions, thousands of more coins will move into the shielded pool, increasing the privacy of ALL users.
All of the deincentivizing becomes amplified too if the price increases, which means as new users are added, they will be more likely to enter into a ecosystem where z addresses are the default, rather than t addresses.
Now of course this can not happen before sapling, or probably even before 2020. But we need to start discussing this now if we really want z to become the default. I don’t believe just an increase in usability to be enough. This economic push, while possibly controversial, will be beneficial in the long run.
T addresses were a huge mistake in my opinion. I understand that they were a nessissary evil to get Zcash off the ground, but the fact that there was no long term plan to deprecated them shows a huge oversight in what is otherwise an amazing invention.