Theft has meaning. It means taking someone’s rightful property against his will by force or deception. Taking money from taxpayers and giving it to team owners qualifies. If the government has that much excess cash uit should give it back in the form of tax cuts or rebates - to the people who have paid it.
Taxation for the legitimate purposes of government is legitimate, but taking from some people and giving to others, whether by taxation or eminent domain, is theft, actually robbery, because it’s taken by force, or threat thereof.
To agree with your definition of ‘taking government money and giving it to team owners” as theft requires assuming that the government purpose is illegitimate. If a government body with power to tax does so, it may be bad policy, but that tax is not on its face, unconstitutional. In like manner, government policies that spend money on stadiums may also be bad policy, but may not be constitutional, unless there is a provision in the state constitution that bans government spending.
Federal government is one of limited powers. State government is one of plenary powers. That means that use of either of those policies is a good idea. There are many bad ideas that are completely constitutional.
That doesn’t mean that the constitutions are flawed though they may be. It means that government is not something that the people allow to run without supervision.
Subsidy of a business by a government may be bad policy without being theft.