I believe that we always should aim for the maximum utility when introducing new features. Staking by itself not really creates that much value. Basically it’s just promise not to sell for a certain time at the core. That could be rewarded, sure, like 5% APY or something like that might sound reasonable. But if someone thinks that timelocking tokens should be massively rewarded he should come down to earth. Vast majority of COMP tokens already is vested or in treasury, small amount of free floating tokens isn’t really a big deal, so holding or selling for that portion of tokens is quite irrelevant in big picture.
However, if staked COMP is usable as collateral, that is quite a product offering which simply doesn’t exist currently. And i’m not talking about dust holders like single or double digit COMP holders, who while obviously would benefit from that as well, but since usd value is relatively small, not that much. But for holders who have 4 digit and above it’s a solid proposal: lock your COMP for a certain period, have your voting rights intact, use it as collateral to put your money to work. Basically contract risk aside, you have the only risk that in case of becoming undercollateralised some or all your COMP could be liquidated. There’s no liquidity risk or anything else associated with borrowing.
Frankly speaking its actually a better deal for VC than vesting. Like much better. Should be there from beginning, but late better than never.
As for rewards it’s not even necessary for such solution, certanly you can fairly easy earn with borrowed money. (which would actually benefit both protocol and wider ecosystem of defi more) I’d say weighted voting power would be a better reward. Depending on a duration of “stake”, voting power could count as 1 for two votes or whatever multiplication is appropriate.
I’d say while we could leave staking rewards as possible opportunity, it certanly could be better spend in other way. For example, COMP rewards could be distributed for liquidity providers in COMP/ETH markets or other pairs on important DEXes. It actually doesn’t even need to be developed in-house, there easily could be collaboration with like sushiswap to distribute COMP rewards on their platform.