Buying a card that's twice the price (and then some) just so that you can not use it is a bananas strategy. You must have some pretty terrible case airflow too, as I've had many 250W+ cards, used them to their full potential and never had them "boiling the whole case". Even when paired with extremely thirsty and hot CPUs like an overclocked 3970X. Not really a problem if you actually set your fans up properly. You certainly don't need to buy a ridiculous overkill card and then use it to only 25% of its potential to have relative silence. I just sold a Palit GTX 1080 Jetstream that was completely inaudible even under full load for hours at a time, and I have my case a couple of feet from my ears. The fans barely spun on the thing thanks to the massive cooler. I have no doubt that you can buy RTX 2060s and 2070s that are similarly functionally silent and would be far more suitable. Of course, you suggest that you have money to burn and don't care, which is your perogative I suppose. You'd think you could sort yourself a few NF-A14s out with that in mind though.
When running RE 2 remake to achieve 75, or even the 144 supported by the monitor, didn't put stress on the GPU.
In games like RE 2 or DMC5, I can't honestly tell the difference if running over 100fps. Or even 75. But to do that, the 2080 does without any trouble, even saving energy and pulling less heat. The Vega 56 had to be full-blown to delivery such performance, some times dropping, and at 200-215w, the heat generated is a lot.
I'm using a small case, true, the Phanteks P400S, but considering that the PSU is fully isolated from the system, I'm using a 12cm back, supplied with the case, 2 X 14cm exhausting at the top and 3 X 14 cm pulling at the front. The CPU using the Dark Rock Pro 3.
The main problem with the Vega 56 Nitro was the cooling, I assume, as the hot air was being blown straight on top of the M.2 and the side window, not outside the case, as any other GPU I ever owned.
When you touch the glass window, it was uncomfortable, unable to hold more than a few seconds.
Not the case to burn money. Got my HD7970 on release and just changed last January.
I think that buying a more expensive GPU, and using it for few years is better than changing GPU every year or year and a half.
In other scenarios, I'm running everything I'm playing at 2k, max, no issues, and the GPU should keep like that for few years, just the case to go easy on a few settings eventually or in the near future.
Just as comparison, same small case, same setup, running benchmarks, which certainly will push any system available: the Asus HD7970DCU was acceptable warm, just noticeable fan noise, but not too much. The TheM.2 temperature, around 40C. Sapphire Vega 56 Nitro, hot and the fan noise slightly more than the HD7970. The temperature of the M.2, was nearly 75C. I would guess the side windows slightly cooler than the M.2. the XFX2080, slightly cooler than the HD7970 and slightly quieter. M.2 temperature about 35C.
Considering the performance and the power drain, and especially the TDP, yes, the Vega 56 is poor. Specially those non-blower models where unless water cooled the heat will stay inside the case, and unless you build a case of fans, will always be a nuisance.