No, no they haven't!!
He has always played a one and two touch game. He's always played with flicks and tricks, these things rarely come off, they are low % even in 2016/17/18 seasons but they way we played, in a high pressing, ultra-aggressive possession style meant we were constantly on the ball and regularly attacking, it was fun. The attacks were also supported, so when flicks didn't come off we were so high up the pitch there was another Spurs player to win it back or the oppo was pushed so far back they had no out ball, so we regained possession and started all over again. Whilst playing in his best position, within this style of football he was at the heart of everything we did, because we were attacking and not sat in a low or mid-block as we have been the past 2.5yrs.
I haven't said, "he's had a good season" (I don't think anyone has had a good season). I've said he hasn't declined as a player, he's playing/been played in different positions (absolutely NOT in his best position) for the best part of THREE seasons, during this time he played almost an entire season injured too. Yet still, you and others judge him based off not playing in his best position and when we were a great attacking side pressing high up the pitch, compared to us now camped on the edge of our own box hoofing the ball long.