is there any benefit (or cost) to my city's library system if i check out an ebook, make a drm-stripped copy, and then immediately return the drm'ed book so somepony else can enjoy it, vs if i just not even bother and download it straight off libgen?
does the library keep track of how many people check the book out for weeding/logistical purposes, or get charged per checkout, or does it expend One of some artificially scarce number of checkouts the library purchased as a license?
is it better for the author somehow to check it out via drm'ed ebook instead of via libgen, if i was only planning on borrowing it from the library anyways, rather than purchasing it?
It depends on the specific vendor and the contract with that vendor. If you're using Hoopla or any of those "you never have to wait but you can only check out X items a month" services,, then every time you check out an eBook the library is paying the vendor an amount of money. Like with Hoopla every time someone borrows a comic book it might charge the library $4. Which is why the library sets a maximum per user per month, to stay within budget. A lot of library systems are moving away from services like Hoopla because this isn't sustainable since we want users to use services we pay for but Hoopla only makes sense if people don't use it much. So if you're borrowing those kinds of books and then ripping the DRM, then you're costing the library money when you could have not costed the library money. I guess that's bad? But like, the way I see services like Hoopla is you shouldn't be stingy with it. Your tax money has allocated for you $30/month to spend on reading comics or whatever so go use it to read comics. It's a better use of tax money than the police and using the library helps make the case for increased library funding overall.
If you're using Overdrive, or any service where there's a limited number of "digital copies" that can be checked out at once so sometimes you have to get in line and wait until one is available to read it, then the library kinda-sorta "owns" that ebook copy and it does not cost the library anything for you to borrow it. The only downside to borrowing it is that someone else can't borrow it until you return it. The benefit to the library is that increased usage numbers for the library helps make the case for more library funding (or continued library funding.) The library always wants you to use it. It's a weird situation where spending our money is also how we get money.
As for non-monetary pros and cons, again it really depends on the vendor, the specific contract, and what you consider to be good or bad. A lot of libraries have as part of their contract with Overdrive something where the library automatically purchases an additional copy of a book for every X holds on it held simultaneously. Like if ten people are waiting on one digital copy, the library automatically buys another copy to shorten the line. If you've ever wondered why a library might arbitrarily limit you to having 6 holds on digital books even though you can have more than that for physical books, this is to make sure you "only place the holds that matter to you" to save the library money. So yeah, it costs the library money, but that money does go to the author (but mostly to Overdrive and MacMillan or whoever)
Weeding of digital collections is weird and more complicated than physical collections. I've never had to do it myself. Space is not as much of a premium so you really don't have to weed as much. Though some contracts will charge an annual amount to the library based on the size of the collection as a "hosting fee". In general when weeding the library is going to look at how many times an item has been borrowed and how recently it was last borrowed. If you borrow an item, you're extending its lifespan in the collection by a good chunk of time.
Borrows also inform the collection development decisions made on what kinds of books to purchase in the future. If you're borrowing a lot of sci-fi novels, that does make the selector more inclined to purchase more sci-fi novels then they are more popular. This is where borrowing library books rather than pirating becomes good for an author. If you're borrowing Becky Chambers books from the library, then the selectors are going to make sure to buy the new Becky Chambers book when it comes out. If nobody borrows her books, then the selectors won't purchase the newer books by this author.
So that's good for the author, but it does mean you're causing the library to spend money. I guess. But like, one single circulation of an item is not alone enough to influence that whole decision. Other people also need to be reading it. So it's more of a grain of sand forming a pile situation. Also, ebooks and physical books are often developed separately because the people who read ebooks are often not the same people as the ones who borrow physical books. So if a book circulates a lot as an ebook it doesn't mean we'll be buying more physical copies.
Does this help? IDK I don't really see there as being a difference to the library if you stripped the DRM or not. Just don't tell anyone that you're doing that. We don't want companies like Overdrive to implement more restrictive policies and surveillance technology to prevent it.
