Does tourism add value or devalue heritage sites?

In my opinion, tourism adds value to heritage sites but devalue the heritage present in heritage sites.

When tourists visit various heritage sites, they will have pay a certain amount of money to view these attractions. This will cause an increase in income for the country and greatly contributes to the value in these heritage sites. Futhermore, it will also show that these tourists are actually interested in these heritage sites and thus make these heritage sites seem more valuable and worthy.

However, through tourism, the heritages be devalued. Due to an increasing number of tourists, various places that are not related to the cultures such as McDonald's or KFC may be also built to satisfy more customers. Therefore, the heritage sites may consist of places that are not related to the heritage, hence devaluing the cultures and heritage of that place.