The thing is, computers have dedicated hardware to deal with binary numbers. Compared to using strings (or other representations), they allow you to do math 100

The thing is, computers have dedicated hardware to deal with binary numbers. Compared to using strings (or other representations), they allow you to do math 100-1000 times faster (probably even more). When you actually start programming, you start getting used to these limits, and realise that for 90% of programs they don't matter. If your program ever did reach those limits, there are libraries you can switch to to get around it, which use alternate representations. But these can get quite slow, and hard to use. So in summary, the best description is "performance".