Very nice you care about that! (Filesize, bandwidth, resources in general). 👍
I'm actually very fine with 360p, as I watch on a smartphone or an old tablet. (Talk formats like #MadeInGermanyPodcast or #TheGrapevineTV)
And I do make an effort to get exactly that (not more/bigger), when I download videos with #youtubeDl (-f 18) or #NewPipeLegacy.
My reasons are exactly that: Filesize + bandwidth:
1. If the file it to big, I can't store many videos on my tablet (I download a few when I'm online, and then watch them later #offline )
2. If the file it to big, it takes to long to download.
#Filesize, #bandwidth, #resources -> care for that, don't waste them!