I don't detect much hysteria. Just individual extrapolation and generalisation where it is difficult to say whether it is imaginary or has some base in facts and reality. What I do see is a cacophony of links from the internet and comments and opinions, which, while interesting, appear to be barely or not at all related to the specific situation of Santiago de Compostela and Galicia as a tourist destination. Of which we appear to know little.
Take the newest example: A long quote from a
US Legal Forms website about a 90 days rule concerning AirBnB that does not apply to Spain or to Santiago or to Barcelona. The net quickly delivers confirmation that such a rule exists, not only in parts of the USA but also in Europe, namely in London. However, the London rule applies only to lets of "whole properties", i.e. whole flats or houses, and not to a room or two within someone's apartment [aka as flat
![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
] for example. And anyway, while issues are similar in many cities, the housing market in the UK, especially in London and the South East, is complex and significantly different from Spain.
Then another long quote from a New York Times article from three years ago about Barcelona and their then new "
ban, which took effect on Aug. 6 [2021 and] sets Barcelona apart as the only major city in Europe to have forbidden short-term private room rentals, even as it continues to allow the renting of entire apartments — so long as the owner of the property holds the appropriate license." It is actually a long and detailed article about the developments in Barcelona but there is no mention of Santiago and of the specific problems that Santiago has or may have in the future and how they tackle them.
What transpires from these linked articles is the fact that this is mainly a question of legislation and regularisation of the local housing markets and employment markets by the local administrations - and this includes detection and elimination of illegal and unlicensed lettings to tourists. There is little if anything that the one-day pilgrim visitor can do in the respect.