Engrams ( muscle memory esque stuff) plays a huge part in climbing performance. The easiest way to get better at climbing is to climb a lot. All the moves you do while climbing get put into a database in your brain. The more movements you do the more movements are in your database. When you are starting out climbing this database is empty, you have to think a lot about every move, potential ways of doing it, and use trial and error or some reasoning to choose how to do every move. This is energy sapping both physically and mentally. The more you climb the more your database fills up, meaning you spend less time thinking about all the possibilities of how to do the next move and make quicker decisions using your past experiences. The more you climb, the more of this move to a more subconscious level. Your brain has gained a better understanding on how your body moves and makes the decisions about some things for your. You may consciously decide you want to put your foot on a certain hold but your brain also decides to engage your core a certain amount, pull harder with your calf to shift your weight over your foot etc. All things that if you individually thought about would take forever but when they are combined together means you move smoothly and efficiently.
This database is the cause of you having a certain style. It could be slabs, corners or overhangs. If you climb just one style then you will be good at it but your brain wont know how to apply what it has learned to other styles. Because of this you need to climb your weaknesses as much as your positives. If you are a good slab climber but you are weak on overhangs then go to boulderworld once a week and work on your steep wall/overhangs. If you never do this then you will never be able to.
There are downsides to this database.
The main one being it remembers EVERYTHING. If setters set bad routes that force you into overly awkward unnatural moves then this will get added to your database of moves. When you are 3 metres above gear, pumped out your mind meaning you cant think straight, all you can rely on is your database of moves to get you through it. If it is full of awkward unnatural shitty moves then you will try and apply some of this meaning you end up falling 7 or so metres in a flailing pile of failure. This is why people say ‘Bad setters make bad climbers’.