There are still different generations though.they are the same architecture in everything but name. RDNA2 is not much different than RDNA1. if you don't do any raytracing related tasks they should perform basically the same, only that RNDA2 is more power efficient.
they literally could have named it RDNA+ (like they did with Zen+) and noone would have questioned it, but it's better PR to add that 2
You can't compare cards from different vendors, architectures or generations without getting inaccurate information.