That is how they are entered by a human, yes. Then they are converted to binary and processed, like everything else. There is no need to add two version numbers

That is how they are entered by a human, yes. Then they are converted to binary and processed, like everything else. There is no need to add two version numbers together, but as they only ever increasing, its sane and efficient to store, and compare binary. Everything in software takes data in one form and processes it into another. There are no 'strings', there are no version numbers. There is only binary. They simply did not give enough space to store it, thats all. DNS is a perfect example, which stores serial numbers internally as an unsigned 32 and has worked for decades and will continue to. But they chose the format of YYYYMMDDnn which will last far longer than a 2 digit year.