It was profitable to do so a year ago, it was simply dangerous politically. Now given Trump is in office and aligned with Musk, it’s politically beneficial.
If an activity is profitable but the government can prosecute you for taking place in that activity, there in no correlation. That’s the point.
Advertising was dangerous because there was a perception that the previous US government would politically prosecute anyone who opposed them. Companies advertising on X, and hence supporting opposition such as Musk, would fall into this category.