Cleveland clinic says says about coffee's laxative effect:
Researchers found that 29% of coffee drinkers report a desire to poop after drinking coffee. The feeling can come pretty quickly, too. (In as little as four minutes!)
And about lactose intolerance (same article):
An estimated 65% of people have some difficulty digesting lactose, which can lead to restroom runs. Lactose intolerance can cause diarrhea and other gastrointestinal (GI) issues within 30 minutes of consumption.
That's a big motivation for me, too, but I'd say it's about equally that I want archival of the best stuff for when rights holders pull their catalogs from the services I stream. I used to think that was mainly for the more obscure stuff, like local bands' early albums that I can barely find anymore, but recently I've noticed albums missing from main services (Tidal and Spotify, in my case) for bigger acts, too.