Group payments was never about facilitating easier payment for guests - it was all about calendar blocking and ratcheting up figures/valuation ahead of an (eventual) IPO.
Each and every Airbnb member has a nominal valuation figure on their head, so obviously, the more members that join, the higher the company valuation.
With group booking, each person in the group had to sign up to become an Airbnb member. In my case, for example, my max guest count is 12, so instead of 1 Airbnb guest being able to book for their group of 12, all 12 were forced to sign up for their own Airbnb accounts - a cumbersome, time-consuming chore at the best of times, particularly when Verified ID, with all its glitches, is required too. This was why the guests were given 4 days to complete as opposed to a much more reasonable 12/24 hrs. (It was technically 72 hrs... but then, when one or more than one of the party failed to pay, Airbnb generously gave the other guests on the booking a further 24 hours grace to either pay the balance between them, or to contact the host and ask them to drop the price to the amount already paid. So 96hrs, or 4 days, in total)
Needless to say, this resulted in the ludicrous facility becoming waaay too much trouble for both Airbnb *and* booking guests (who very often bailed out, and buggered off to other platforms where they didn't have to jump through laborious hoops to simply book a place to stay for a couple of nights) And yet another farcical Airbnb initiative bites the dust.. *not* because Airbnb "listened to hosts", but because it was utterly unworkable, and became much more hassle than it was worth.