I believe the games that were compared to, engine and bug wise earlier in the thread, were Red Dead Redemption 2 and Zero Dawn: Horizon, if I understood people's letter's correctly.
RDR2, according to VGC, is just under 20 million copies sold.
H:ZD is just under 6 million copies sold.
Skyrim is at 26 million copies sold, which is fantastic, but not much better than RDR2 has done so far, and Skyrim has been out for a long time now and this is counting remastered versions as well as VR and Switch release. The original Skyrim games, which is probably a lot more fair to compare to, were at 16.52 million if we are including Switch, and just 15.37 million if we are just counting 360/ps3. I suspect RDR2 will be closer to 30 million when its all said and done, and H:ZD to be at least 7-8 million, so Skyrim is basically right between them but certainly not blowing either of them out.
RDR2 is not really a great example of a great RPG. Also is it not a great example for being glitch free, early weeks their were reports with people being stuck in the story because of a glitch and if you click funny glitches on youtube in RDR2 you find plenty. Skyrim passed 30 million in November 2016 before switch release/a month after PS4/xone release and before the PSVR release making it one one of the top 10 selling games ever or close to.
' The Elder Scrolls V: Skyrim, the studio’s previous game, may have been an even bigger hit, selling 30 million copies in the five year since its release. The average Skyrim player, according to Bethesda, has spent 150 hours inside the game’s vast open world.'
Yes Skyrim is known for having bugs but it is also known for being one of best game experiences for a lot of people. In fact most hate towards Skyrim doesn't come from bethesda haters but from Fallout fans.