In the past couple of years we've seen an influx of stats and KPIs that try to quantify the beautiful game, especially for players that don't record goals/assists. When I first started following the game it was primarily goals, assists, clean sheets and depending on where you went, tackles and blocks. Now we have chances created, aerial duels won, xG, progressive passes, pass accuracy (short and long), dribbles, passes in opposition 3rd, shot to goal conversion %, sprint speed, progressive runs, touches etc. I think on one hand, yes, it's good to get some more metrics to try and assess performance, but at the same time we might get to a point where we try and force fit statistical models into the game.
One stat/KPI I wouldn't mind seeing, is a "critical contribution" metric for strikers/forwards/creative players. Why? Goals tally alone doesn't illustrate the full picture.
Take for example Icardi. Since dude moved to PSG he's been banging in goals left and right. But if you look at his goals, most (at least from what I've seen) come when PSG is up 3-0 and the game is in the last 10 mins, essentially a garbage time goal that has little bearing to do with the outcome of the game. It'd be different, than say Icardi scoring the only goal in 1-0 win in the SFs of the French Cup.
Just my musing (been looking at spread sheets all day).