In the past, Nintendo really did care about availability, especially in Japan. Right up until the early 2000's you could mail in Famicom disks and a few yen to get a copy of whatever FDS game you wanted written to it. Heck I bought things from Nintendo's online store back then and the sheer backlog they kept available was great. I ordered a brand new Nes controller, N64 controller, and Gamecube component cable along with a few copies of some SNES manuals they happened to have lying around. When they ran out of those copies, they'd just send you a scanned and printed version instead which was, well it was SOMETHING at least.
The Earthbound guide was uploaded some time ago, but it's only a matter of time before Nintendo redesigns their sight and just decides to cut it rather than maintain it.
Right now, the very best retro preservers are the fans.
http://www.replacementdocs.com/ for all your scanned PDFs of old game manual needs.
https://www.analogue.co/ provides cycle-accurate reproductions of old consoles.
https://krikzz.com/ provides well designed ROM carts for numerous systems and for certain ones will also provide cycle accurate reproductions of add-on chip functionality.
https://limitedrungames.com/ https://retro-bit.com/ https://castlemaniagames.com/ These three provide (among other things) many authorized reproductions of retro games. Sadly, while even heavy weights like Capcom have authorized repros, Nintendo has never gotten involved with these companies. Shantae (Gameboy) prices are so ridiculous online that I went ahead and bought a repro instead.
https://www.retrorgb.com/ provides very detailed and accurate information for anything you'd care to know about playing those retro games.
https://www.youtube.com/channel/UCjFaPUc...193mnW_w1w This channel provides a lot of information but what's notable is the number of videos dedicated to hacking various systems to allow homebrew and, yes, running games without the original media on them. I hesitate to say "piracy" because there are many legitimate reasons why someone might prefer to run games off a memory stick instead of UMDs on the PSP, or simply prefer a reliable way to play backsups of their own games.
However, what option is there when we're talking digital-only? At that point, you either do insane things like buy entire PS4s just because it's got something exclusive like a copy of P.T. downloaded to it, or you just accept that things like money were made up in the first place and digital ownership is kinda an imaginary concept and just... steal it mate.