I'd reasonably expect software to run forever insofar as the environment it's run in doesn't change. Essentially, no OS or dependency updates - network is inevitably going to get broken.
Anecdata: My Wii (2006) console has had a few hardware issues I've fixed, but the software is just as responsive as a decade ago (though many external networks/servers have shut down). Homebrew community is very much alive and has expanded its utility.
Anecdata: My Wii (2006) console has had a few hardware issues I've fixed, but the software is just as responsive as a decade ago (though many external networks/servers have shut down). Homebrew community is very much alive and has expanded its utility.