Cardinal vs Neon Tetras

I wouldn't necessarily say they are hard to keep, I just can't keep them in my water. I tried and the first batch just generally didn't do well and eventually died off. I came here and asked advice and everyone said they wouldn't do well in my water (the hardness/high ph would lead to kidney problems and significantly shortened lifespans) but I was stubborn and continued to try with a couple more batches of tank raised which lasted a little longer but eventually died out too. All of mine acclimated fine initially, but wouldn't make it past the 6-9 month mark. Most places I've read put their ideal ph range as under 6 and very soft water. They can obviously adapt to conditions that don't meet that ideal, but my water has a ph of 8.3 and a kh of 19 which is apparently just too much to expect them to live in long term. I've had luck with other soft water fish (rams specifically), but their ideals aren't as extreme as the cardinals, plus they have been captive bred for much longer so are generally more able to adapt to tank conditions than wild-caught or 1st generation fish tend to be.