this is a very interesting topic to me and one i've considered a lot as someone who collects media across all formats, but mainly vhs.
i agree a lot with plasticseaslug that a lot of 'overconsumption' is based around getting rid of the item. with fast fashion hauls, these people are wearing these clothes once and then tossing them out which lands them in landfills more often than not. fast fashion as an industry is also incredibly harmful environmentally and haul culture contributes to its continuation. things like collecting stanley cups (and if anyone remembers its predecessor of a hype, hydroflasks) imo is just wasteful because you dont need more than 1 stanley cup/hydroflask/etc, they're reusable for a reason. part of the selling point of hydroflasks were that they would survive straight up car fires and the like they're so sturdy, and yet there were tons of people collecting every color, size, etc that they put out. i see that a lot with stanley cups now.
i think tiktok definitely contributes to this problem because of the ease of access to the content as well as how popular the content is able to get because of tiktok's (frankly, terrifying) algorithm. it's so easy to fall down a hole of watching people do various hauls if they pertain to your interests and tiktok manages to get one video on your feed (speaking from past experience). and then people experience a type of fomo, i guess. a desire to have the thing because it looks cool/fun/etc without fully considering whether or not they'd actually use these items before they eventually end up in a landfill and subsequently not doing much to help prevent that from happening.
i think for a lot of people collecting can end up falling into this and it takes effort to build a collection mindfully rather than simply buying to buy. i buy all of my media second hand, and if i decide i'm not using it enough, i sell it to someone who does want it. i still have quite a lot of media but i do legitimately use all of it that i keep. my friends will come over to watch vhs/dvd/blu rays and eat pizza, or sit around the record/CD/cassette player and listen to a few albums while having a conversation. my collection largely exists because i like it ofc, but also because it facilitates social interaction for me. i dont have to worry about if x streaming service took a movie or show off because i own it physically, we can just watch it through that. it also makes a great conversation point since i have it on a bookshelf in my living room. people will often be surprised that i have vhs tapes and ask if we can watch something the first time they're here which makes it easy to pop something on and have something to watch or discuss if they're that type of person haha
as for digital hoarding, i think it also becomes an issue when it starts coming to whether or not you're actually using this data actively or simply having it just to have it but not for like. ethical reasons but rather i think it's better to just have what you need so you have space for anything else you may need and don't need to go through your whole drive clearing it whenever you need space! but maybe that's just my anxiety lmao i have a lot of music on my computer and i would consider it a hoard, but i listen to my collection every day for the entire day. on the other hand, i used to have a lot of movies and tv shows on my drive because i thought i would get to watching them faster if they were - turns out i was wrong! lol i think it's important to do a clean of our drives (and hardware! don't forget (: ) regularly just to make sure we aren't taking up space that could be used for things we want to actively do/use. however, collecting multiple drives that you aren't running regularly doesn't really seem like too grand of an issue to me if again, they're being used in some capacity (or repaired). even if you were running a bunch of them, as someone in the thread said earlier, the energy consumption is negligible when compared to something like cryptomining (which eats up energy AND water (: ) or a big corp's energy consumption!
ultimately, corporations and capitalism are the problem when it comes to consumption and it's multiple harmful effects. they're the ones pushing it and while we as consumers can always be mindful of our consumption and limit it, it'll take larger action to truly change these things. because despite our best efforts to be mindful and reduce our consumption, corporations and capitalism will always push that this is the consumer's fault for consuming in the first place like they did with personal carbon footprints which shifted the blame for fossil fuels from the corporations pushing fossil fuels to the consumer for, well, consuming them.
im not sure how to wrap this up, but really i think haul culture is inherently harmful (not even gonna get into the other problems with it beyond environmental impact mentioned earlier and the industries it tends to support as i don't feel this is the space lol) while collections can be properly and mindfully managed to reduce how much the collector is contributing to haul culture and subsequently landfill waste and other harmful things.