Consider that to by my favorite era of gaming, with the 64 not far behind. I currently have a gamecube, and sometimes find some games or action sequences to be pretty intimidating (such as some boss battles in Metroid Prime, etc).
I'm used to this, of course, but there's a difference when it's a 2d platformer versus a 1st/3rd person game. We've come a long way from dispatching Bowser's seven naughty kids in SM3.
Anyway, I was watching the final boss battle to Ninja Gaiden 1 (NES), which I never beat, and clicked on a montage of Boss battles for ninja gaiden 3 (360/xb1? Not sure). Man, those looked insane. I felt overwhelmed just watching those, and it feels that there would be no way I could enjoy that as a gamer.
From time to time I consider buying a PS2, just so I can experience Shadows of the Colossus. Looks like that degree of "epic ness" has been far surpassed.
Side note....yes, I feel old now.
It's took me almost 18 months to Platinum Killzone Shadow Fall and that's not including any DLC, I'm currently playing GTA V and that's also an absolute time sink both single player and the online component.
So I find them intimidating in a different way - the size of modern games.
I think being overwhelmed is a good thing, I personally love most 3-D games and I say the more insane and massive the better. Personally I don't care about getting all the achievements/trophies in games, just beating it is usually enough for me(sometimes I might go out of my way to get collectables if they're interesting enough).
GTA V isn't nearly as big of a time sink as RPGs like say Skyrim are.