I feel like I say this in a lot of posts ..but this is normal difficulty meant for the average player of the game and the average player does not like to miss multiple hits in a roll. Even someone whose never read the first thing about DnD can tell from the first few encounters and 'tooltips' (modifier notifications on the bottom left), how to position your characters for the highest hit chance. Yes this reduces the usefulness of 56+ spells and abilities, but instead of spending a limited spell slot/round to setup each and every combat, you can preplan positions and pre-sneak towards critical enemies. This is as much about misses as it is keeping the player engaged and having something to do with multiple avenues to approach each and every combat encounter. I mentioned the difficulty because for all we know there could be a 'core' mode or simply hard/insane for people who do not mind combat taking an hour or more, this would be a hard no for the vast majority of people they expect to buy this game though. RTwP could work the core rules a lot easier since there isn't such a huge slow down but that of course would limit so many other things 5e has to offer. I imagine bonuses will be tweaked to some extent, but 75%+ with advantage will remain with the skills you listed maybe providing guaranteed hits at some point or lasting longer rounds. I'm sure there will be combat encounters where these skills will matter a lot more than what we've seen, after all this is the easiest beginner friendly portion of the game. Every new level 1 tabletop session has a unknown handicap not based on the player character's level, but the actual player's knowledge of the game, it's ruleset and experience in whatever setting they are presented. Larian has to make the game with the assumption that a level 1 character doesn't even know what a d20 is, much less has memorized which spells to take for a better hit chance. Yep, this screws with CR, means hits land more often, and balance has to be shifted towards number of mobs, available terrain, their HP, enemy items and AI. They chose the hard road on this one, not to just copy paste existing balance.
I hope they give the rogue something special, but even as is he's still the highest damage dealer due to the multiple offhand attacks and ease of melee sneak bonus. BG2 had class specific items and I think that would be one way to add artificial boosts and bring back rogueiness to the rogues....guaranteed backstabs on start of combat, static poison or bleeds on weapons, short rest aoe silences from stealth, I think there's a lot they could do here to help out.