Before streaming became an option you had to buy an album to hear it. I have bought many albums without hearing them first. Some lived up to my expectations others didn’t. Sometimes I thought maybe I just need to live with an album and eventually I’ll get it.
Also, I always wanted to have a great collection. I’ve always enjoyed music and I have diverse tastes, so I’ve got quite a few albums in various formats. I don't even consider myself a collector let alone a hoarder. I'd say that when your record collecting starts causing problems in other areas of your life, you become a hoarder.
If I were starting my music collection now, I’d stream music and only buy a select few really special albums.
Another reason people amass huge collections is that people just like to buy stuff. Women call it retail therapy. If you’re familiar with Stuart Varney from cable news, he is originally from the UK and he said his observation as someone raised elsewhere is that Americans are happiest when spending money.