Walk me through the opposite scenario where block times were even longer? Thinking of ways to boost hash. Maybe adjustable block-TIME?

I pose this question after hearing about plans to make block-times shorter, so why not actually make block-times longer to try to always incentivize hashrate. Would this be an answer to the security budget long term as the blocks would be more transaction-dense and therefore lucrative for miners to mine, not to mention the block-subsidy could be increased at the same rate that the blocks are lengthened (as is the inverse suggestion of cutting the reward in response to faster block times) to not change the 21M mined by 2140 schedule.

Maybe if there was a way to have adjustable block-times along with the adjustable block-size? The adjustable block-times would ensure that BCH is confirming full blocks full of fees for the miners, and depending on how long it took to fill that block would equate to how much of the coinbase reward came along with all those fees. If transaction volume is consistently bumping up against the limit then the block-time could decrease along with the block-size increasing to always find the happy-medium that would not only ensure small fees (for adoption and the end users) but full blocks of all of those small fees for the miners (hashrate incentive for miners.)

What would really be the downside of going this path? This would be a full embrace of 0-conf which would only get even stronger with more miner security. I think we should focus on ways to boost hashrate as that is really all that BTC has on BCH.