I'm not an offensive line expert and don't claim to be. When a Chiefs linemen gets beat, I know enough to say that's bad. When they block their guy, I know enough to say that's good.
That said, Pro Football Focus ranked every offensive line in the NFL through the first half of the season and concluded that the Chiefs offensive line ranks 22nd in the NFL. Without having watched all the other offensive lines, that feels about right I suppose.
The Chiefs are an awful pass blocking team, ranking 31st in the league in pass blocking according to PFF.