How do bandwidth considerations figure in system design?

Apologies if this seems too stupid but I'm a complete system design noob preparing for interviews and I've started going through Grokking. At the start of each topic, they consider the storage, traffic and so on. One of those things is bandwidth. In every solution, I can't seem to find anything mentioned about how we'll deal with that much bandwidth except for put in a few more servers and add some load balancers everywhere. I assume real life solutions are a bit more complicated and this is significantly dumbed down. Could anyone explain what other factors are considered to tackle bandwidth in real life? Blind Tax yoe 4 TC 24 LPA #software #engineering