During 2013..2015, the times different scaling proposals were analyzed, I proposed reducing the block time to 1 minute. I did some research that ended with the DECOR+ PoW consensus algorithm as an alternative to Nakamoto Consensus.
Some more info here:
https://bitslog.wordpress.com/2014/05/02/decor/The DECOR+ protocol is what powers the RSK Bitcoin Sidechain (check
rsk.co).
There has been a lot more research about this since 2014. My current understanding is that shorter block intervals down to 1 minute for Bitcoin are ok because block propagation has improved (however the blocks would need to be 1/10th of the current size). For even shorter intervals, more cooperative consensus protocols are required to prevent the generation of stale blocks to be a significant disadvantage.