The Radeon VII card isn't bad from the benchmarks middling between the 2070 and 2080 and people act like it's some great disappointment. I think HBM2 has it's place though realistically once AMD has more of a budget to work with I'm sure we'll see GDDR6 and HBM2 high end cards come out at the same time. Plus people doing video editing think 16GB cards are a boon since they keep running out of GPU memory on other cards (and Nvidia's wacky RAM numbers just make my roll my eyes, 11GB? Seriously?).
Radeon VII is an RTX2080 competitor half a year later. RTX2080 in turn got a lot of deserved beating for being almost the same performance at the same price point as GTX1080Ti year and a half earlier. There are use cases where Radeon VII makes sense but for gaming it is a tough proposition. 16GB RAM is pretty much its only boon.
RAM amounts have everything to do with being as optimal as possible. Nvidia has found memory bandwidth is not a significant limiter for certain cards even when amount of memory or amount of chips is not power of two. xx60 cards with 192-bit memory bus as well as xx80Ti (and RTX 2080) with 384-bit are an example of that. That being said, 11GB and 352-bit is still a clear exercise in product segmentation where there tends to be a Titan that has a full width of memory bus.
AMD lost that choice in high end when they went for HBM2. They could not populate one or two of HBM2 stacks or populate them with lower capacity dies but it would just not be worth the trouble. In fact, as they have all the pieces in bulk, having choices there is likely to make it more expensive. In midrange/low-midrange they are stuck with 256-bit memory bus as this currently competes successfully with Nvidia's 192-bit memory bus with its better compression. 256-bit is still faster but not by much in this comparison. If AMD found doing 192-bit or 384-bit buses would be beneficial they will also do it in a heartbeat.
What do you want to see happen in the market and why?
More competition. I hope Intel will join the fray. I hope AMD will get its R&D together and work out some of the things its GPUs are struggling with.