I don't think Arsenal can win every single year, but in a decade he's done almost nothing. Don't forget that a huge amount of the spending City/Chelsea do is completely wasted, new managers come in and just don't like certain players, spend to make their mark. Again a longer term manager has more time to pick and chose players, should get better deals because lets say you take over City you're expected to win that year. Think of City spending 18mil to get De Jong when he could have been free 6 months or a year later, they did it because of the immediacy of their needs. Arsenal don't face that problem, they could and absolutely should have identified a half dozen top DM's in the past 4-5 years and bought any of them when it made most sense for the team.
Ignoring the DM position every year for years on end which hurts the team every year is not good management and nothing to do with finances, it's to do with Wenger being stupid.
Wenger is also peeing money away year after year on the likes of Diaby, Rosicky, he threw money away on Santos, Monreal.
What you keep doing is associating most of Arsenal's problems with squad, many are but many of those could be fixed. Their are great deals constantly, only urgency ever really makes teams overspend and as said, this isn't a problem Wenger has faced.
The problem with Arsenal is not the squad, or transfer spending, but tactics. These are all entirely Wenger's problem.
Being unable to become competitive at defensive or offensive set pieces in a decade is completely Wenger's fault. Refusing to play differently against better teams is entirely his fault. It's some bizarre philosophy he's decided is the better way to win... except he doesn't win, he's failed to win with this idea for a decade but he persists.
There are a dozen, several dozen ways Arsenal can improve without spending a single penny, if one year we sat back and played differently against the top 6, maybe didn't win but didn't lose any of the games maybe we could be in with a shot of winning the title.
Nothing that is failing based on tactics, management, training, nothing has been fixed in years. The point of talking about Dortmund or Atletico is that ANY team can have a great year, how have Arsenal not had a good year in a decade under Wenger? In actual fact most teams have great years where they play better than the sum of their parts, Arsenal do not. Wenger's substitutions are shocking, his inability to see out a game is laughable, his tactical naivety cost us points every year.
There are LOADS of problems at Arsenal and almost none of them have anything to do with money, talking about money alone is just being pig headed or ignorant.
Today Arsenal refusing to have people back defending is nothing, nothing at all in any way to do with money. Playing Gibbs in a big game again despite messing up in every big game of the past 2 seasons, again nothing to do with money. We sent out Coquelin who has time and time again come in and done a good job, but then gets ignored, he's played well at fullback and defensive midfield. We're paying his wages afaik while he's on loan but we're not getting any use from him.
The majority of Arsenal's problems aren't to do with money but are about things Wenger can but refuses to change, problems that cost us game after game, year after year, competition after competition.