Random doesn't mean ineffective... like everyother species had 5 noses and 3 legs. Random mutation is subtle, and occurs 1 in a Million based pairs, but when you add up all our base pairs it occurs a good amount of times. Sometimes mutation was beneficial, sometimes it wasn't. The ones it wasn't beneficial for died out, which is why we didn't see those bad mutations juxtaposed against good mutations when adaptation occurs.
Consider evolution like a game of blackjack where you have 1 billion players, each with 1 billion dollars and each player is consistently betting 1% of their worth. Each player represents a species. Each hand represents a new generation of that player. Every player starts the same, but overtime you would get players who are extremely poor and eliminated, and players who are extremely rich and doing quite well. This wouldn't occur because of a god-determined fate, this simply occurred because of probability.
You could liken an "environmental" change to the "casino" setting a cap floor of 50 Billion dollars , where all players without 50 billion dollars were eliminated. In this you would have some players who would scrape by barely and others who have no problem meeting the cap., but most would be eliminated. These players who met the cap, weren't determined by god, they were determined by probability (randomly) which was how well they did in each previous million hands.
Maybe you make an argument that god's plan was the casino and the blackjack dealer was god... but still ostensibly everything occurred randomly.
It's hard to look at the advancements of humans and say it occured randomly, but we're not talking about one blackjack hand that made everything work out. We're talking about literally billions of hands which determined anything from our height to our chemical reaction to a hormone.