This is not wear but overstrain/overload to the point the rubber tears.
Maybe try the powerflex black series. they're shore95a and maybe stronger (as the PU is stiffer/harder, it may be able to withstand more force).
You need a style of bushing that can carry the surfaceload, so made with an inner core material that can stand more N/mm˛
I know hardrace makes a lollypop with a Polyetherimide core, which is very hard. (obviously the harder the fcab, the more NVH). Turner probably has something similar in Delrin or such.
Did you use enough of the supplied copper grease? The knurling on the inner bushing needs to be saturated with grease (it acts as a grease trap)
I see some grease but no copper coloured grease. Or has powerflex changed the type of grease they ship it with recently? (last powerflexstuff I got/installed is already 2 years ago)
Anyway you can get a replacement for free as they offer lifetime warranty I believe. Maybe you can get the black ones for free
