Does Microsoft withhold tax?

In terms of payment, in addition to the commission withheld, does Microsoft also withhold tax? And why? Why do we need to pay tax in the USA, or be liable for tax in the USA?

Microsoft does withhold Tax in regions where they manage tax on behalf of the publisher – when you set up your Tax profile, they asked questions regarding your organization to determine whether or not you will be liable for tax in the USA – this can be reviewed here: https://partner.microsoft.com/en-us/dashboard/account/v3/overview (on this screen, navigate to Tax Profiles and review)