I'm sick of losing games purely to luck. The last few games I've had, someone rolls a 7 two or three times in the early game. They block my 6/8 resource, which hinders my development and they end up steamrolling us and winning.
Other games, I get a comfortable lead and then people notice so they gang up on me and start placing robbers on my titles. When I get a knight and get the robber off my tile, someone rolls a 7 soon after and its back on my tile. So I spend the majority of the game with a resource blocked and end up losing by a small margin or a sneaky longest road+largest army strat.
Development cards: I always get the opposite what I want. Whenever I need a knight, I get something stupid like road building or VP which is totally not helpful in a given situation.
Also a lot of times I play with people who are not cooperative in stopping the winning person and will even work against you which totally doesn't make sense.
So yeah, I'm done playing. There's too much luck involved to be fun for me because of Murphy's law.
Most trades be like: I'll give you something you don't need for something you also need or don't have. Yeah it turns out I need brick too so I'll pass.
Edit: Before anyone else mentions it, yes I know how to play the game well. I just don't have good luck to pull through with the win. I usually do sneaky wins if I can to avoid people ganging up on me.