The subsidy is "use it or lose it", meaning it is treated as income and pay rate applies.
Suppose in the first year the average delegate pay rate is 30%.
That means only 1bn would be added, not 3.1bn like the theoretical maximum subsidy.
Furthermore, the 2.1bn are NOT recycled into the delegate pool, so the theoretical max supply drops from 10bn to under 8bn.
Meanwhile the subsidy *rate* has still decreased on schedule, because the amount by which subsidy_pool_remaining decreases is independent of pay rate.
All this means is that early voters have to be proactive about only approving high pay-rate delegates to people or groups which add value and want the DAC to succeed. I know and trust enough AGS whales to think that this is no more dangerous or "unfair" than giving ourselves a huge dev preallocation.