A thousand times this. Look at the time you spend farming/raid chests/quests/titan/war/tournaments/events on an average day. It’s easy to see how adding almost any tedious data collection/entry tasks are easy to burn out on. One starts to realize ‘I spend enough time in the game, why am I doing this tedious work for the game while not even playing it’.
That never precludes me from trying, or recording screens for someone else to possibly take the mantle in the future. However, it severely tempers my expectations that it will actually be done some day.
With that in mind, the easiest to track is average titan damage. If you keep screenshots of the titan list, there are OCRs in Line, Discord, and through APIs to convert that image into text and you can streamline the base data rather efficiently. Since you can take screens and just fill in the data when you have the time, this is the least effort involved for a KPI. You can record the titan variety and derive stats on each titan color and level as well.
If you want to get in the weeds, you can use that same trick to capture screenshots of all the war hits. Using this, you would see which team members defenses were picked on the most, how each individual fared in one-hit/cleanup mode, and a sort of +/- net on whether the opponent scored more on them than they scored on the opponent. I did this analysis once because it was rather tedious setting everything up. Interesting, but not worth my time, imo.
Once again, I can’t stress enough that the data is continuously streaming in. The best option is to crowd-source it. If you do it alone, my guess is that you probably won’t last more than a couple of months before missing a couple of data points or burning out. If your alliance really wants it, then lean on them to contribute work for it. I would say that in preparation, it doesn’t hurt to save screenshots in an album or folder so that you can fill in data for times before you set up your methodology was established.