I imagine for the most part that is enough for most people to achieve those results.
My problem is that I keep meeting and speaking to far too many people who have sworn by less that 'best practice' QT protocols or ich management or russian roulette or snake oil and claimed long term success without incident or death, only to be wiped out and never seen again. They rarely come back for the good of other reefers and say, "you know what? I got it wrong. Don't do that".
My frustration comes with the intellectual dishonesty or at best, ignorance posing as expert opinion that we see so much of on this topic (not a reference to you). There's a guy on Youtube right now who's sponsored, only had a tank for nearing on two years, has never lost a fish and therefore is encouraging others not to QT or treat prophylactically and spreading opinions like, Ich is like a cold.
I know few people will go to the extent that I might to manage the risk of ich or other diseases and that many of them might be just fine. I also know few go to the extent that they claim they do.