"I have a friend who is interested in putting together a system"
Not knowing much about your friend, it’s difficult to set priorities about what is important to them: Mac/PC? Dog/cat? Internal combustion/EV? Zappa/Hank Sr. Etc.
I would start by putting your friend in front of the most amazing system you’ve ever heard (within a reasonable commute from your home). This should create a strong emotional response (or, perhaps even loosing control of basic bodily functions) to illustrate what the the "ultimate system" looks and sounds like when it is finished. If the response is similar to the watching the first 12 minutes of any RomCom, perhaps he/she may want to pursue another hobby?
Second, I would make sure they have some "skin in the game." The pursuit of their system has to mean more them than it does to you. The more vested they are in the project, the more they will appreciate it. The more they appreciate it, the more they will enjoy it. And, the more enduring the hobby will be over their lifetime.