Interesting, I do believe Opengl has overall worse performance than DIrectX though right?
Though I've heard Vulkan might solve the issue.

No, it is just different. Directx is made for games, OpenGL made for many things (games, 3d graphics etc...). So there are some developer that used to use only directx. Or they used to use a engine that exported a game with directx 11 and opengl 3 (for example).
Also Vulkan (like Directx 12 and Metal) use all the same logic (use the low-level machine code).
But with modern engine there is really no difference because if you are a developer that use Unreal Engine or Unity3d you can export a game for both directx and opengl (last version of both).
yes a real anti-tamper would only prevent me to modify the binary (exe for windows).
if you use steam drm and put it in offline mode you would be able to play it on the same machine forever.

with denuvo you cannot.

Well, most developers/publishers see piracy as a serious issue. IMO, they think if they manage to stop piracy, miracle will happen.

IMO piracy is not a good thing. without piracy we would not have drm in the first place.
but there are better solution than DRM to fight piracy.
- update a game many times (try to find the updated version of a game on torrent every time it is more time consuming than buy that game).
- fair price (there are many people that with a fair price say "fuck I just buy that, it is easier").
- educate people (why so many people bought the witcher? because CDProject always "sell" their DRM-free policy. their fair behavior etc...)
- less trouble for paying customers
- exclusive, and events
- online stores (we all love to get a game immediately, without getting up from the chair)

etc...

fight piracy with an anti-piracy software only make people who paid for it angry.
fight piracy with good pratices make people loyal.

it might win if enough games are released DRM free. i believe the "game" will only end as demand for cracks lessens.
if DRM free releases become popular enough, we will end with few companies selling uncrackable software and no one using it.

What about users who *want* an older version for whatever reason? For example, maybe there's a fun glitch that the developers decided to patch out? Or maybe I am interested in a particular version for historical purposes (example: Skyrim version 1.2, which had some bugs that are not in any other version, like dragons flying backwards and resistances not functioning properly).

slightly disagree with this part, the story has to end at some point, surely

Galaxy's rollback feature or piracy. :P

A developer is still the owner of the copyright, they have the right to withdraw a certain work from the market (a bugged version of a game is not a good advertising). they can also release it after "10 years" because there is no reason to hide it anymore, but they have the right to don't do that (after all if you release a paid product you need to provide assistance).

You still have the right to buy and backup a game on your HDD (so that if the developer update it you can still have access to the old version).
When they prevent you to make a backup with DRM, there is a big problem.
piracy only impact few months with big name that use Denuvo.
there is no reason to update it many times after 1-2 years

GoG always has an eye more for its clients. Trust is the reason why it has so many loyal customers.
but Denuvo problem is on Steam and Origin so we have to think about Steam and Origin problems

PS. I don't think piracy for old update if you already own a game is the reason for the use of denuvo.

That's because the developers who did shitty job and not Denuvo's.

A truly "uncrackable" DRM might be invented, anything is possible. Denuvo is so difficult to crack some scene groups have already pretty much given up on some titles.

I think the battle against DRM shouldn't be technological battle, because that's a losing battle. It should be psychological battle, ie convincing gamers to reject DRM and to demand releases of games on platforms like GOG or Humble.

my brother had the same problem with dark souls and windows live.

Well avalanche studios developed both Mad Max and Just Cause 3.

Do you really have a right to buy and make copies of that product? I think that is a legally grey area. I mean I disc image for my own personal use (if I ever use discs now I have so many on GOG) as the CD player nearly blows up reading discs, but I would suspect I am not totally within the letter of the EULA on that regardless of the use.

Yes, my experience was GTA4, got it on release, spent days trying to get it to run, on the phone to R* etc. It only ran for about half an hour before stopping completely. Years later I tried a cracked version, played it for a while then deleted it and threw the original away, waste of money on shitty drm and a shitty game anyways. Never to buy anything from R* again. I think that is really the key. Have started building a list of game makers who I won't buy from again, based on DRM or other shady practices, thats really the only power we have is not giving them money.

Note, as for Dark Souls, well, that has a good shout for being the worst game ever in any circumstances.