Do you realize that Tottenham's decline occurred when Harry Kane left the club?
Tottenham has always been the same to me, same team that their performance can never be relied on. Last season looked like they have already progressed past the stage they are in already, but they are back there. Richarlison was expected to be a replacement after Harry Kane, but he could not fit that shoe, Solanke who has joined the club is not receiving enough support from other players in the club to score goals, they do not pass the ball to him often maybe also because they do not yet trust him enough to deliver.
I don't expect them to sack the coach just yet though. He should be given more time to try fix the team.
Tottenham is one of the most renowned teams in the Premier League. However, this team has not competed for the title in any season. Despite performing well, we see this team in 4/5th position in the table. And the coach cannot be blamed for this every season. Tottenham management thinks that they will succeed only if they change the coach. This idea is wrong.
Tottenham management should strengthen their squad. Prepare big funds to buy players. But Tottenham management never provides big funds to buy players. Tottenham is performing very badly this season. Tottenham management will probably sack their coach. However, if the squad is not strengthened, we will never see an improvement in Tottenham's overall performance.