a decade? no offense, especially if you're a millennial - ten years isn't that long. I have hundreds of compact disks approaching three times that old. "ad hoc torrent" sounds great, but you're at the whims of seeds, and cease and desist letters. This also doesn't take into account monthly bandwidth "caps".
There's somethings i have for background noise and visuals that i got on YT - what, i should stream it every time? even at 480p this will eat into monthly caps. What about things where i know i have one of the only full (as in needs no fills) copies of some media from the 1990s? Less than 5% of the stuff i keep is contemporaneous with the download date.
If one is just downloading "current" things and then figuring out how to store more of it; then i 100% agree. That's a waste of space and time. Chances are you're paying for the right to stream it, and if you don't care about caps, burn the shareholder money for all i care by streaming it whenever you want to see it. Ideally at 4k.
I'll keep downloading and storing stuff i find important - someday when/if youtube deletes some channels i have backed up, or a production company pulls all their content off of streaming platforms, or a different archive with convoluted steps to access content ceases to exist - i'll still have it, with subtitle files, searchable, locally. It happens a lot more often than you think.