None of this makes any sense. For one thing, Spurs don't have a better top-to-bottom squad than Arsenal. Spurs' main advantage is that they lucked into a legit world-class striker coming through their academy and Arsenal didn't, and it would cost Arsenal at least 40m to buy a striker of Kane's age/caliber if they could even find one for sale. But at most of the other positions, Arsenal are just as good or better. Spurs don't have a playmaker anywhere near Ozil's class; as much as I love Dele Alli, Sanchez is the best goalscoring/attacking midfielder in either team; Cazorla is the best ball-playing mid in either squad, etc. Kane, Aldeweireld, Rose, and maybe Dier are the only Spurs players clearly superior to their Arsenal positional counterparts right now.
Arsenal are in third because a) Leicester are having a one-in-a-million season where (at least until the last couple of games) just about everything has broken right for them in terms of injuries, refereeing decisions, chance conversion, etc. b) Arsenal had a couple of key injuries (Cazorla especially, Sanchez, Welbeck also) while Leicester and Spurs didn't, and c) Giroud and Walcott both turned into pumpkins in the second half of the season and the team's finishing has been absolutely dreadful, leading them to significantly underperform their peripheral chance creation stats:
Arsenal are a very good but imperfect team that basically got no breaks this year. Some of that is that their strikers have weaknesses (although both Ozil and Sanchez have had atypically low conversion rates this year too), but a lot of it is just random variance. Sometimes things just don't break your way. The Patriots went a decade without winning a championship despite having the best coach/QB combo in the league. Variance is a bitch. And it's very different from Chelsea (who quit on their coach because he was mean to the lady physio and tanked the season to get him fired), Man City (whose players just can't be bothered to play hard in a lot of their away games), or Man Utd (who have an expensive but incoherent squad assembled with no strategic vision). Probably Wenger should have strengthened the squad more, but in the wake of the ongoing Chelsea debacle and Man Utd's struggles and Man City's petulantly throwing away points because they're lazy, I don't think Wenger gets nearly enough credit for his man management and his ability to maintain the team's performance level. Arsenal don't always play well, but they never quit on their coach, or regularly mail in games because they just can't be bothered. They've had some bad losses, but they never go into a tailspin as a result (thread title notwithstanding). And they never have a down season. If this season has proven anything, it's that big clubs don't have some god-given right to finish in the top 4, and it takes real work and commitment to do it consistently.
There are legitimate questions as to whether Wenger is the right guy to take this team to the next level (he doesn't always get his tactics right, some of the hyped youth players aren't developing as well as hoped, and his, well, odd transfer business has been covered to death), and who knows what's going on financially with the ownership, but there are very few available managers who could plausibly be better now that Klopp, Ancelloti, Guardiola, etc. are all off the market, and obviously it could be a whole lot worse, as Man Utd have shown in trying to replace Ferguson, or as Liverpool have shown as they struggle to find consistency post Benitez. And Arsenal can't afford to just throw giant wads of cash at the problem like Man Utd can if they miss the CL for a year or two. Arsenal have money, but not the kind of money where they can spend 65m on a player and then dump him a year later at a huge loss, or buy 35m youth prospects, or 25m players who don't fit their tactical system just because.
For the first time since the 2002-04 period, I think Arsenal should probably be favorites for next season's title, depending on what happens in the summer. Leicester won't repeat. Chelsea may have a housecleaning, and that was a thin, aging squad at the back anyway. Pep is a great manager but that roster is not currently set up to play Pepball and I think it will take him a year of transition. Utd's front office management is a mess. Spurs will be good again, but unless they strengthen significantly they'll need some luck to keep up a campaign on 2-3 fronts. And Arsenal are due for some positive regression to the mean next year. I don't know if Wenger can win them the title, but I do know that calls to blow it up in order to "reset fan expectations" or have "purging fires" are outrageously stupid. My advice for Arsenal fans would be: