Somebody else who doesn't have the first clue. More things do go wrong with mutation, but they don't survive in the population because 'going wrong' is defined as hindering survival and reproduction, so those changes quickly die out. When things go right, they aid survival and reproduction (that's again what 'going right' means), so they tend to spread through the population. That is natural selection and that is why all the 'good' changes accumulate in the population.
I know how the theory works; lady luck and the gods of casino science. But common sense says, random changes to an otherwise organized/ordered system like life, will be net destructive. If we start with a large population, and employ random changes to the DNA, and say one such change is beneficial for natural selection; one lottery ticket winner, the rest of the population will still have genetic based defects; did not win the lottery but lost money. The next cycle, we start with 90% of the original population, etc., do this again, until it goes extinct. In this scenario, selective advantage more often goes to the least sick and not the most vigorous.
In modern times, there are many illnesses that can be attributed to genetic factors. Can you name any modern beneficial genetic changes, discovered over the past 10 years? We use genetic based protocols to compensate for bad genes, but we do not add progressive genetic change to the population, since it is not so clear cut, like the defects.
How about we do an experiment on you; hypothetical, where we will work under the assumption, if we could change the right gene, we can make you as smart as Albert Einstein. That is lottery ticket grand prize. To get there, you need to buy tickets which means you need to allow us to randomly alter your genetics, until you win the grand prize. You will need to buy a lot of ticket or we will need to make a lot of random changes, each with the hope of winning. I bet you get sick way before you become smart. All but one of these tickets will be a loser, with the winning ticket, even if randomly distributed on any given day, will typically come too late, before sickness dominates and the smart is not useful to you.
The biggest problem with genetic theory is its lottery ticket mentality, which fixates on the accurate catalog of past winners. But it ignores the much larger number of past losers; house of grim reaper wins due to all the bad tickets, even if one wins. There is an addiction behavior; fantasy and faith, that helps promote gaming addiction, even in science theory.
There is a way to fix this and the theory of evolution. Water needs to be placed on center stage, even before the DNA. Nothing works properly in cells without water. There is no substitute for water, that can make enough things work, to allow the expression we call life. This is not a lottery ticket argument, but cause and affect based on facts. Water is a sure thing.
The fluid nature of life is based on secondary bonding forces, with the properties of water based on the strongest of these secondary bonding forces within life; hydrogen bonding. Each tiny water molecule.; H2O, can form up to four hydrogen bonds with other water molecules. This makes water, pound for pound, the king of secondary bonding forces in the cell and in life. Since all things in life have to interact with water, including the DNA, secondary bonding stability within the water globally and locally dominates at the secondary bonding level. Random does not apply when one entity dominates; loads all the dice.
In terms of water and evolution, change is not exactly random, but has a sense of direction; loaded dice, connected to water trying to maximize its secondary bonding potential. When that happens to change on the DNA, life advances. There are sweets spots. Water sour spots that do not benefit the water, tend to be altered to better fit into the water matrix. This allows water to lode the dice and beat the odds, so the organized systems of life can net advance; evolve.