For "big POWER" like POWER8/9/10, they are clearly not positioned at that market. However, there are small Power ISA chips for embedded systems and companies like NXP still make them (the Amiga community even tries to shoehorn these into desktop systems, to their detriment, IMHO), and IBM has done "little POWER" versions of big POWER chips (the G5 being a scaled-down POWER4 with AltiVec, for example).
The long version is https://www.talospace.com/2020/01/another-amiga-you-dont-wan... but the tl;dr version is that the Amiga diehards who would buy this still want to use Amiga as their daily drivers, yet these are CPUs that a 15-year-old-plus Power Mac would mop the floor with. It's just handing their detractors another stick for a fresh beating. As a strictly retrocomputing solution that wouldn't be a problem, but that's not how these newer Amigas are positioned and by playing into the "Power is dead/underpowered" trope they're bad for the community as a whole.