The RGB lighting is surely worth it if you are one who needs an above-average feel while using your PC.
It is not necessary for your rig to be a very pricey one to add colors, you can add lighting even in an entry-level desktop if you want to do so. However, these better suit those who are gamers or are invested in some creative work.
There aren't many instances where a user who only uses the PC to access the internet uses RGB, as the components having such characteristics aren't available by default in all PCs. As long as you have a suitable case that actually allows you to show others how attractive the interiors are, it should be worth customizing your PC with lights.