Someone's gotta do the packaging for almost everything you buy at stores.

Go to a convention: someone designed all the signage for the con, the badges, as well as the individual booths and any amount of what they may be selling. Plus all the fliers and stickers whatnot people want to hand out.

Gotten anything shipped lately? Did it come in a box with more than one color on it? Those are probably a couple of spot inks, rather than CMYK. That's a thing where instead of mixing a color from little dots of the primaries, you load up a tank in the printer with ink mixed to a very specific color.

Got a collection of Pokemon cards? Pull out those extra-rare ones with the foil and gloss and stuff. The precise process for actually putting those on the card varies and may not involve anything resembling "ink" at all but a lot of those are specified as spot inks too.

I could probably come up with more examples but there is a cat milling about my ankles who is very vocal about her need for some playtime. :)

Automated RGB-to-CMYK translation has gotten better over the years but if you are a pro, you will probably have had enough nasty surprises when that fails that you know how to do it yourself, maybe you're even like me and work in CMYK to begin with as a rule so that you never have to fuck around with finessing that translation.