Volta never became a gaming gpu because according to jensen it was too expensive to produce. So presumably that's what that "poor volta" thing was about as it was widely expected to be a gaming gpu at some point but it never happened.
Found an article with quotes saying as much: https://www.techspot.com/news/70584-nvidia-volta-gaming-gpus-not-foreseeable-future.html
That poor Volta came out long before it was known that there was going to be no Volta Gaming GPUs. Whether AMD knew or not or whether they intended it or not, doesn't really matter. That "Poor Volta" raised the expectation levels of the performance of Vega. It was terrible marketing that completely backfired.
AMD have 50 years of history, the majority of it making very good and efficient products, my knowledge of it spans 25 years.
Due to a combination of a few mistakes and a lack of money AMD had a few years of products that were not good, so did Intel, so did Nvidia.
They were working through their problems and getting past them before this current generation of GPU's, i saw no reason why AMD's bad run should continue when they had already got past it.
You said it was nonsense when people thought that RDNA 2 would use a lot more power based on AMD's presentation slides. People were basing that on the last few GPU releases, not what AMD released 40 years. Vega, Polaris, Fury, Hawaii. Vega, Polaris and Fury were all hyped up based on AMD slides or AMD marketing. And they weren't all that great when it came to power efficiency either.
So, it's not really surprising that people were taking AMD's slides with a pinch of salt and questioning how they were going to achieve that 50% over RDNA 1 without increasing the power consumption.
AMD did really well with RDNA 2. It's the first time they are competing from the top down and without any issues. Now they have to do what they have done on the CPU side. And that's continue to release good products.