Guys, guys, relax. Both ways are feasible.
Here's a real life example:
My first playthrough of Wizardry 6, I was young and foolish. I didn't care about getting 100% out of my party, but the seeds of powergaming had already been planted by then. So I'd roll for a good long time to make sure everyone has 18+ bonus stats- something I simply considered part of any Computer RPG at the time. Then I'd play through the game without ever multiclassing or looking up what items dropped where. Not even using a walkthrough- except to get the fabled ring everyone talked about.
But I still had fun! Sure, not everyone in my party could hide. And true, the game was (sort of) hard on Normal, but being difficult just felt like it was part of these games. Wizardry 7, with the same party, felt brutal, and 8 felt a bit like it was harder than 6, but not as bad as 7. Still, I rolled with what classes they were and with whatever gear dropped for them, without re-load scumming treasure chests or pick-pocketing.
When I played it again, much later, I had grown a little wiser- Fallout and Arcanum had taught me that what I enjoy the most is seeing numbers go up and becoming more and more powerful. In fact, I played Bloodlines in such as way as to get the highest possible XP from every quest (rather than "playing my character")- so conversely, on my next Wizardry 6 run, I'd make sure every character had 21+ bonus points at the start and they'd all become Ninjas at some point so they get Hide and Critical Hit, plus I looked up what rare items drop where and tried to get them to import them.
Now you'd think that I completely obliterated the game with this kind of powergaming, right? Well, no. Wizardry 6 features something called "Expert" difficulty- and if you tell me you're supposed to get through that without using every tool at your disposal you must an ubermensch, because that setting is completely unhinged balls to the walls madness.
Edit: I guess this is kind-off outing myself, but even I never, ever played Fallout "in-character". No sir, it's always either "Speech + Guns" and getting everything to the minimum required for dialogue options, or picking less-used skills for a "challenge mode" run, which will still use all possible optimization that is feasible. Playing in-character is... well, it's kinda gay, you know?