Criticism of PFS

I've played around 7 PFS games at my FLGS and in general, I've found it very disappointing. Pathfinder was sold to me as "a game with difficult combat that you have to take seriously." Except that all of the fights have been very, very easy. I don't think there has been a single fight where the presence of my character made a material difference between us winning or us losing. IE, the party, reduced to just 3 people without me, could have still won easily. And if nothing that I do matters, then, why bother?

The last scenario I did had only one encounter in it, against a witch with 3 zombies. I'm pretty sure the Barbarian (premade, level 1) in our group could have won the fight alone. The Guardian (custom, level 3) in our group definitely could have won the fight alone.

I did a scenario once where, on his turn, the barbarian dashed through a hallway full of obvious traps, setting of four of them, to run into the middle a room full of enemies, getting surrounded by 6 of him. You should not do something that reckless and expect to live. He was fine, of course.

Combat seems more a race to see if you can even get a single hit in before the encounter ends. I'm not asking for some horrible death grind, I just want our choices to matter. If running through 4 traps to get surrounded by a ball of enemies is as effective as employing some kind of strategy, then our choices don't matter. There's no room for creativity when "I run up and hit them" is always optimal.

Some of the scenarios have "chase scenes" in them, or "investigations" (?), which are similar. The GM lists some skills relevant to the scene asks everyone in order to choose one of them and make a skill check. I really don't like this. You just look at your character sheet and pick the largest number next to a skill and roll. And then you do it again, and again, and again. There's no room for creativity when all you do is pick the biggest number, so what are we doing? I could understand if just once per mission, but we spent about an hour doing this 9 times each.

If the GM instead described the scenario and then each of us decided how our character was trying to contribute to the mission and chose a skill to roll, at least we would have to do some thinking ourselves, instead of "choose the largest number and then repeat 8 more times". What is the point of this?

My friends only play DnD, so PFS is the only way I can even play Pathfinder, but at this point, it isn't even fun anymore.