It's much more nuanced than this.
In Pakistan, we ourselves have failed to duly acknowledge our position as an ancient civilisational legacy nation. Thus, we have failed to capitalise on the extensive market for such tourism in particular. The security issues in Pakistan do exist but no moreso than in multiple nations of similar size and/or population density where criminals tend to be armed with firearms. Tourists still go to Central/South America, USA, Russia, the Middle East etc. and our historical legacy sites are potentially of greater significance than any of those places.
Pakistan should be in the position Egypt is in today with regards to tourism.
We seem to be edging in the right direction. But of course, the butthurt qom to our east repeatedly interferes with our efforts to assert and define our own historical legacy, which is a unique confounding issue that Egypt and others never had to deal with.
Until we can wrest control of the narrative underpinning the Indus Valley Civilisation from the false and jealous usurpers, the status quo will persist.