This has a lot more to do with consumption than with production. Most of these islands are small, and it's unrealistic for them to have large populations or a heavy tourist industry without desalination plants. Energy needs to become cheap, and honestly, wind farms and solar can help with this.
I'm the article they point to a lot of factors as to why this is now becoming an issue: increase urbanization, increased industries, increased tourism.
They do say collecting rainwater is probably part of the solution, but if the other things keep on growing that won't always be the case.
Call for experts to participate in the IPCC Scoping Meeting for a Methodology Report on the Carbon Dioxide Removal Technologies and Carbon Capture Utilization and Storage
Low and middle-income countries in Asia face significant disparities in scientific capacity and ability to influence public policy, which is likely to affect responses to future pandemics, climate change and technological advancements such as Artificial Intelligence, according to the International Network for Government Science Advice (INGSA).
I originally read the title as "it is more difficult to influence public policy in least-developed countries based on this study" but it appears it's actually "it is more difficult for scientists to advocate for science-backed policies in least-developed countries."