I wouldn't call his Spurs stint a failure at all. The man took over a midtable team in relegation form, whipped them into shape and got them into the CL places by the end of the season. Last season was a resounding success where he hit the ground running and exceeded expectations.
This season isn't even that bad -- Lloris has been horrible (not Conte's fault), they lack depth at CB, their only serviceable fullback was an aging Perisic until they signed Porro recently, they lack creativity in the midfield, their forwards were overworked and Son suddenly turned into shit after having his career season. Despite all this, they're within sniffing distance from CL places, and it's not like 5th is a bad result for Tottenham. They're probably going to dismantle Milan and make the CL QFs, which only happened three times in Tottenham's entire history (in 1962, 2011 and 2019).
Everyone knew he was about results and not beautiful football. He's been getting said results and he might even win them a cup this year which was supposedly Spurs' most important goal.