Yes, the validity of geographic spread is limited by the fact that respondents are volunteers. Even so, I believe it will be informative to see if and how access to resources varies in the subset of people the survey reaches. If there are significant differences based on country, for example, that could inform resource distribution in a potential intervention. Of course, it would be important to follow up to confirm that the differences present in the results are representative of the larger population.
Yes, the validity of geographic spread is limited by the fact that respondents are volunteers. Even so, I believe it will be informative to see if and how access to resources varies in the subset of people the survey reaches. If there are significant differences based on country, for example, that could inform resource distribution in a potential intervention. Of course, it would be important to follow up to confirm that the differences present in the results are representative of the larger population.