One can argue conferences and conventions and business travel is still tourism, but not the kind that comes to appreciate the city, people, culture or history. SF will remain a destination for the starry-eyed tech grad and entrepreneur despite everything, that is not what I am commenting to here.

As for total spending, 2.3% is not even inflation in a normal place, let alone the most rapidly inflating city in the world. If you adjust for 2017 vs 2018 dollars, that is definitely a decline. By my estimate the cost of most things a visitor would spend on has gone up by at least 5% on average between those years (as the report you link posted, hotels up by 6%, and airbnbs up by far more than that, and similarly with ticketed entries, transportation and food).

This report paints a far rosier picture than what is actually happening when you account for the rate at which prices of things tourists pay for are going up relative to the tourism revenue numbers themselves.

More viscerally, if you live in SF for 2-3 years and hang around tourist spots often enough, you can just feel this viscerally as the lines outside shops have shrunk, numerous shopkeeps are just dusting their shelves with no customers, and gifts look unpurchased for years.