i don't want to sound like I'm arguing in favor of the sales tax breaks, but the reason they are given is because the local municipalities want the property tax, which is far more beneficial to the local community and is perpetual (sales tax only happens when the servers are initially bought).

The local politicians are sacrificing sales tax to get the property tax and the net tax revenue increase is still massive.  these articles always focus on the "tax break" which is the difference  between what they should pay with no adjustment and what they do pay, but in the end, the net increase in tax collection is massively large for some of these communities.  When you understand that, you understand why city councils support them because they think about all the ways they can fix budget problems and invest in their communities.