If Microsoft did not enjoy the tax breaks, it might have settled somewhere else in the first place, and the overall economic activity and tax revenue would be smaller. Everyone else would have to pay more, or be happy with smaller public spending.

Lower taxes, but also lower needs for spending due to lower population.

There is an argument that attracting company's that compensate well has a net positive impact. But, it takes a lot of of people to make up for these costs. If you assume an extra ~3,000$ per person per year over the areas average that's 230,000 workers which seems unlikely.

Remember everyone involved wants to make this seem like a great thing. But, even negative sum games can make someone rich.

Maybe, maybe not. We are talking about 30 years ago. It is now one of the largest corporations in the world. Even if you buy into the corrupt world of tax incentives, they generally come with some sort of expiration date.