It's kinda good they use such old systems, as the vast majority of pollution occurs during manufacturing of devices since we usually use them only a handful of years. Iirc the break-even point was somewhere around 25 years, as in, upgrading for energy efficiency then becomes worth it (source: https://wimvanderbauwhede.codeberg.page/articles/frugal-comp...). 15 goes a long way towards that!
On the other hand, I didn't dig very deep into the ticket history now but it sounds like this could have been expected: it broke once already 4 years ago (2021), so maybe planning an upgrade for when this happens again would be good foresight. Then again, volunteers... It's not like I picked up the work as an f-droid user either