Maybe there is some slightly different environment that we would still call hydrothermal in which RNA is sufficiently stable.
The idea in caption to Fig 4 that building blocks do not interact directly with the environment seems interesting and plausible, but not very well defined. Are you saying a cell interacts with the environment but a single gene does not? Or a multicellular organism interacts but one cell does not? The citations 52 and 53 are in fields that are not related to biology and origin of life. So I think this idea needs to be explained and justified in a biological context.