Even without the obvious impacts to market makers and the subsequent price increases to investors, this doesn’t help.

Most things trade with price/time priority. This means that first tie breaker is price but second tie breaker on what fills is who had their order into the market first. This means that market makers layer orders in as early as possible, some strategies I’ve seen layering them weeks or months in advance.

So this proposal would add cost to the market without changing anything about the cancel race.

The real solution to this sort of problem (which I don’t believe actually caused this issue) is the same mechanism you put in any request/reply system, rate limits. Most exchanges have them.