IMO, anyone who can solo speedrun a certain difficulty is clearly not challenged by the difficulty itself. When speed becomes the metric as opposed to completion, the player is essentially taking completion for granted (i.e. the difficulty has been trivialized).
But this is usually going to be the case, since video game companies do not make the hardest difficulties borderline impossible. Even the Nightmare difficulty on the original DOOM was eventually reduced to speedrunning.
*edit: Nightmare difficulty on Final Doom: The Plutonia Experiment is an example of such an impossible difficulty that it has never been reduced to speedrunning. In fact, just last month, 19 years after the game's release, the first recorded single segment, single life run was published:
http://www.pcgamer.c...ingle-life-run/
Could you imagine if it took 19 years for the first player to solo platinum? They definitely don't make games the way they used to, LOL
I watched that speedrun when it came out two months (
) ago, and was quite amazed. I've played the Doom series (including Final Doom) and watched many speedruns, and I know how difficult it is. Everyone should take a peek at that speedrun.
For those who don't know: the de facto difficulty for Doom speedruns is Ultraviolence, the second-highest difficulty. On Nightmare monsters move much faster, attack absolutely relentlessly and respawn shortly after dying - and many monsters can kill you with just a couple hits, as damage in Doom is heavily randomized. In many games a slow and careful approach usually makes the hardest difficulties more manageable, but in Nightmare Doom that strategy doesn't really cut it. Nighmare is used for speedruns too, but not nearly as often as Ultraviolence.
Final Doom itself is a special case, because it was specifically created by hardcore players for hardcore players, and Plutonia Experiment, the latter of the two episodes, was always meant to challenge even the best players. Final Doom (on PC) was never intended to be played by "casual" gamers.
In other words, while they don't quite make games the way they used to, Final Doom was an exception even back then, so it's not really fair to compare it to modern games. But I'd definitely like to see some extreme difficulty levels in modern games.
Btw, one noteworthy detail from ME3 perspective is that in Doom difficulty level doesn't affect monsters' hit points, they die just as easily on Nightmare than they do on any other difficulty. No Platinum bullet sponges there...