I find it really interesting that I keep coming across posts which basically assert "Rogues dominate combat" and "rogues are killing machines" but I have yet to come across the phenomenon in reality in any of my campaigns....
That aside, you do realise that
(1) Sneak Attacks are denied if there's any degree of concealment? (so if the combat takes place at night, or there is an obscuring mist spell going, or the opponent is subject to a blur or displacement (even minor displacement) effect etc) there can be no Sneak Attack?
(2) The Rogue has to be able to reach vital organs. A non-flying rogue could quite legitamately be denied Sneak Attacks against a Fire Giant opponent as all he can reach is the legs.
(3) A rogue who is grappled is dead meat. A rogue sitting next to a 9-headed pyrohydra is going to deal 25d6 damage (in ideal circumstances and assuming you decide the rogue can reach vital organs,) then: grapple, grapple (if the first is repelled by an AoO) then rip, tear, rend, chomp, gobble.
In my experience, fighters are the ones who shine in combat, which is as it should be. Barbarians can take damage but get hit too much (I play a Barbarian - at 4th level my Raging hp are 48, but I'm only AC 13.) A Fighter can take almost as much damage, but gets hit far less often (the party Ftr has only 33 hp but AC 19,) and sure he deals less damage than the Barbarian with a 2H Sword, but he'll deal it consistently, get extra hits from Cleave, can use Power Attack to get extra damage if the opponent's AC is low, etc etc. In a straight-out fight between a Bbn10 and Ftr10 with appropriate (roughly equal value, not ridiculously min-maxed) equipment, I'd put my money on the Ftr every time. In fact, against an average CR10 opponent (whether that be several smaller creatures or a single large creature,) I'd go with the Ftr every time.
A rogue's Sneak Attack allows him/her to be an often useful, and occasionally devastating, melee opponent which is a great improvement over 1/2e backstab, but (s)he'll never come close to a Bbn let alone a Ftr over time, over a range of encounters, or even in the great majority of individual encounters. Given the rogue's skill range, that is IMHO as it should be.