Handicap Apps vs. Self calcs

Hi, basic question: how did people calculate HC before all the apps? They had to keep it themselves right? It’s a pretty simple formula to do so. Issue: I keep my own scored legitimately through a google excel file and have for 8 years before apps were in vogue. I love the customizing and personalization I can do to show trends, keep stats, etc. my uncle and cousins are on high horses saying that doesn’t count and think they can knock my Hc down because it’s “not legitimate”. To me that’s BS. The only difference my way doesn’t present is the accounting apps do for how the course is playing that day, in terms of easy or hard. No argument there. But when I compare what my net HC for a round versus friends for that day it’s never more than .5 off in either direction. So it’s offsetting to me. I get I can’t enter tournaments with it and don’t intend to. I use it with my friends who aren’t obtuse and it’s no issue. I’m basically arguing I’m not doing it any different than people were 10-20 years ago, so what’s the problem. Am I wrong ? Thanks either way!