I'd say 2017 was when I stopped watching consistently. I'd still put the shows on for some background noise, but I stopped watching almost completely around 2018-ish. My interest was already waning prior to 2016, but the brand split got me excited again and for the first year of the brand split the shows, both RAW and SmackDown, were great. When the 2017 draft happened, they tore apart SmackDown and changed the rosters to random nonsense, breaking apart existing stories for no reason. It just became a chore to watch, especially since the shows suck ass anyways.
I remember thinking back about how many changes occurred from 2010 to 2000 or 2000 to 1990 and just how different those years felt and how constantly WWE was changing. Compare the changes in roster, presentation, product, style, production and feel to how WWE has been from 2020 and 2010, and you'd be hard pressed to find absolutely any difference other than maybe 5 newer stars and an LED ramp, they even had the same set for 8 years.