I agree, we’ll gain useful data from the ending of the liquidity incentive program - how much money stays in the pools, what are the unsubsidized fee returns, how much will slippage increase, etc. But, it may take governance a while to process this information and agree on the ideal incentive program. This proposal is meant to be a stop-gap which will keep Uniswap humming and support the user experience while governance builds consensus on a long term solution.
That being said, we can be responsive to any data coming in over the next few days, and make changes to the distribution plan as appropriate 
Uniswap benefits from having deeper liquidity - allowing larger size swaps with lower slippage and a better trading experience. Anecdotally, some of the increased volume since August may be a result of having this deep liquidity available.
If you would like to submit a separate proposal on this, please feel free You can continue discussion on that topic in this thread.