It’s simple. Confirmation times is a wildly accepted term that is used everywhere in the crypto world, 0-conf isn’t there yet. So I argue that people running exchanges and payment processors are just counting confirmation times and not really doing the task of computing the work (chainwork). Some providers require just 1 confirmation. lowering block time to 2.5 minutes means 4 times faster transaction for people.
I think such upgrade should be accompanied with marketing/public relation campaign showing the changes BCH have went through to improve stability (yearly upgrade schedule - double spend statistic) to reduce the possibility of exchanges increasing confirmation requirements for BCH.
Did I say that this should replace 0 conf or that sellers will have to switch to block confirmation after such upgrade. It basically reduces the uncertainty/risk and increases trust in crypto payments for merchants and service providers.
Is it safe to accept $100 0-conf payment[s]?
One additional point is that I’ve seen it multiple times that people are suggesting accepting 0-conf for payments less than $100 which is probably good for many merchants but what about payment processors who have to process tens or hundreds of $100s in an hour? What about payments larger than $100 USD?
I quote part of @im_uname Telegram post:
note that 2.5m will shift current 2h complaints (which sometimes happen) to 30m complaints.
I think this is a big advantage to reduce wait time specially when 1h or 2h blocks happen.