Why in the name of God is stadium stopped then!? Like Gecko said: Greed is good!? Cmon.
There are a couple of answers on that.
First is the storied corruption in city politics. There is a tremendously corrupt governmental bureaucracy. This corruption is not limited to activities within the city limits of Chicago. When I first moved out to the suburbs from the city, I saw that a paving company that shared the family name of two people who were on the village board was getting the lion's share of contracts (and no-bid contracts at that). These are people who are in increasing their personal wealth and everything else is secondary.
Second is that a lot of these folks aren't the smartest people. A lot of the local governments here have suffered financially because of revenue losses in the pandemic. Many are desperate to get an increase in revenues immediately. In order to reap the benefits of what the Bears want to do will take several years to happen. With all the NIMBY folks who are doing things like recall petitions for the AH mayor and village board, are you going to sign off on a deal where the Bears get a huge write down on their property taxes during a multi-year construction/development project?
And don't assume the mayor of Chicago holds all the aces on this either. While he desperately needs to keep all the revenue he can inside the city limits, he cannot appear to be giving a wealthy suburban family a sweetheart deal. The combined assets of the McCaskey family are in the multi-billions and they all live in Lake Forest (where Halas Hall is located). This is the #5 city in Illinois by income and is in the top 100 US cities by income. If the mayor is perceived as giving away everything to keep the Bears in Chicago, he will be a one term mayor.
+1 If the Bears do move on I'll bet it's going to be a stadium (they own) in the City of Chicago. It sounds like the City is going to pitch them a deal they can't refuse, now that the new mayor is pushing this. As far as Arlington Heights goes, I wonder if they've thought about the fact that a new owner of the property could be a less desirable business? Instead of an upscale campus of businesses around a state-of-the-art sports and entertainment venue, you get something horrible like a mega-meat packing business, or one of the nastier (property value killing) things that you don't want there? There is a limit to what the people can limit as far as what a new owner can do with that property. They may gladly pay the taxes but the business itself could be pretty nasty.
I've been following several discussions on the stadium on the local Nextdoor app groups. The opposition to the new stadium is by several of what you might loosely call "grass-root" groups here. Most of the opposition is based on assumptions that I personally consider irrational.
These folks want a business that is fairly profitable so it can pay enough taxes (and generate enough jobs so there are additional income tax, sales tax, etc revenues) to reduce their property tax burden while supporting increased school and municipal infrastructure spending. At the same time, they want businesses that will "fit in" with their communities (whatever the hell that means) as well as not seriously impact their daily lives (no serious increase in traffic, not inebriated partiers in bars, etc).
Basically, they want something that will miraculously provide funding for 30% to 40% of their governmental spending, at the same time allow for a >25% increase in that governmental spending, and not have any impact on the current character of their villages.
Its NIMBYism of course. Every pol has their grubby paws out asking to be greased, every govt agency is salivating at the idea of taxing the hell out of anything that moves, and every interest group wants "their share" of the revenues without the challenges (traffic, noise, etc) that any large scale project brings.
Classic Cook County behavior
Econ 101: Capital flows preferentially to where it is well treated. If you tax and/or regulate the shit out of things, capital flees elsewhere.