Some of the tastiest mushrooms are also the most recognizable, like morels. If you want them foraging is the only option for most people. Morels have no reliable farming methods as far as I know
Foraging for mushrooms is an awful lot of fun. In many European cities, you are often able to bring all your mushrooms to the local food market mushroom expert and have them identified. It's a great service.
I have no problem with that. What you are outlining is procedural and it's been culturally regularized over time, essentially it's self-checking as everyone knows the rules and what to do.
The problem comes when neophyte beginners decide to go hunting for mushrooms. They may think they've a good understanding of what's safe and often they do but it's the odd slipup or mistake that can turn fatal.
With mushrooms there is no margin for error, you're either right and enjoy a lovely meal or you die by a lingering death. It only takes one error for disaster to occur.
Take this story for instance: https://www.abc.net.au/news/2012-01-06/fatal-mushroom-meal-c.... Unfortunately, it's often a change of circumstance, or an unusual set of events that catches people out. I remember this accident happening, tragically similar scenarios have happened all too frequently in many countries.
Have a look at [1]. One is edible without special considerations, the other is potentially lethal if you don't corrently boil it in a well-ventilated room first (and take care not to breathe in too much of what you're boiling off). People are regularly hospitalised for doing stupid stuff like standing over the pot. Most advice I've seen tell people to not eat even properly prepared gyromitra too often (at least one book on foraging tells people to avoid more than one meal a year of it).
If you're experienced and aware of the existence of gyromitra, you'll probably do just fine. But I totally understand if people don't feel confident that they'd make the right call. The colours looks obviously different on those pictures, but try looking at some other pictures to get an idea of the colour variations.
I don't want to put people off foraging for mushrooms, because I absolutely agree with you that many of the tastiest kinds are rarely available without foraging (more often available at markets than in stores, but inconsistently certainly; even gyromitra can be bought at markets in some countries), but better that people are well aware of the potential for misidentification so they seek proper advice and learn how to distinguish them first (and are aware that the risk factors varies greatly between regions depending on which similar mushrooms exists there).
I agree, despite having almost certain knowledge of at least a few of the safer types, I'd never pick mushrooms from the wild.
The consequences of even one badie getting into the mix can be too horrible to contemplate. Often there's no antidote and you're dead within days.