In football, there is no such official concept as deserving and everything should be decided exclusively on the football field and a place in the standings. Whoever takes a place higher in the standings at the end of the season will take a place in the next season of the Champions League, the third is not given 
Well, at least we all know about that clearly. But we are talking about probabilities and other possibilities based on team performance which may differ.Undoubtedly, Arsenal is having a pretty good season, especially considering how bad the start of this season was, but it is still difficult to call him the undisputed favorite in the battle for a place in the Champions League. It is also difficult to call Tottenham or Manchester United favorites, and much of this depends on the club preferences of the person expressing his opinion.
Of course, Arsenal have managed to improve their form so far after we all doubted them at the start of the season. I also don't think Tottenham and Manchester United are favourites, but Conte can make Tottenham better than Arsenal or Manchester United. I'm not a Tottenham fan, but I know Conte is one coach who can improve the performance of the team he coaches for the better.