What was it that in 2015 had you doubting them already? The master plan was public at that point. That was the year they released the Model X - a pretty good year for them after some development hell. I definitely thought there was a lot to be excited about back then. Not invested, just excited about their cars and hoping for a model 3 in my near future. I'm fully off the wagon now of course, but they had a LOT of success 2015-2018, when that continued hard with the model 3.