Yes, the games years ago were much tougher, mainly for the reasons the article highlights and also due to technical limitations and lack of help that's available now. Also gaming has changed and gamers these days simply wouldn't wear a game as tough as what we grew up with. There's too much choice now so it would be discarded for the next title. We also didn't have that wealth of choice that gamers have now.
Two hella hard games I finished that immediately spring to mind are Super Ghouls & Ghosts and Diddy Kong Racing by Rare.
Ghouls & Ghosts made you cry and anyone who says otherwise is lying or hasn't played or finished it. Not only was it unbelievably and brutally hard due to the precision needed but, when you got to the end and beat the final boss, it dumped you back at the beginning to start again. You needed a ring to beat the final boss and it couldn't be collected on first run-through. Maddening doesn't describe it and don't forget, you only had 6 credits x 3 lives - for both run throughs.... I managed it though, through sheer dogged perseverance. That and the fact as gamer back then, I didn't know any different. We bought games and finished them no matter how tough they were. That was the way it was.
Diddy Kong Racing was another that was ludicrously tough. Like Mario Kart, it starts off easy enough but then once you have completed the game, the reverse tracks enter the fray with the dreaded red coin challenges. I cannot describe how frustrating these were. One mistake on any of the 3 laps in a red coin race meant the challenge was over. The coins were so devilishly hard to get that you had pull off slides round trees without hitting anything else all the while trying to stay in the lead without hitting anything or anyone else. The AI was also in full on elastic cheat mode in these races so each race had to be absolutely perfect. They were a nightmare and once I completed the game, I never played it again!
Another toughie was Castlevania - Rondo of blood on the PC-Engine. Very, very hard due in the main, to the awful sprite collision. Doable but, bloody hard.
Tbh, there's lots of tough games and I could probably reel off a shed load with some thought. Weirdly though, I found the 120 stars in Mario 64 no problem.
Gamers these days have it easy. Yes, Demons/Dark Souls are hard. That's not in doubt but, they're doable and actually become easy with patience and time. Same with Trials to a degree but at least with Trials it's almost old school in that if you cock up, it's over. It requires practice. Whilst mistakes in modern games are punished, they're not punished anyhere near as severely as in the likes of say; G&G or R-Type. You lost a life in those well into the game, and you were pretty much finished.