Good point. The new green was decided after the split with iMessage, so technically Apple could have made it a poor color on purpose.

I still doubt it, especially since it’s the same green for FaceTime, Phone, and the icon that still represents iMessage.

Yeah, it wasn't always a bad green. They absolutely chose a bad color on purpose - arguably the world's best design company accidentally uses a painful high-saturation low-contrast background color that violates their own design guidelines for like 8 years by mistake? Give me a break.