Probably no real reason to point this out, but Tsukasa's argument here is pretty stupid, light pollution in urban areas makes stargazing wayyy worse
Yeah. It's more that she's had enough of wandering the countryside in her life and doesn't want to do it- to her, modern conveniences exist for a very good reason. It's part of why she keeps referring to humanity with respect to her preferences in certain places, I suspect: she identifies with human civilization as a whole thanks to her heavily-implied longevity and worldly traveler history.
She probably knows full well about the light-pollution issue, but doesn't care enough because she feels like she's had her fill of looking up at the clear night sky. She only wants to make the arguments that support her preference of just never 'roughing it' ever again in her life. It really makes a lot of sense, with all the evidence about her we'd have up to this point, from chapter contents, the end-of-volume Q&A sessions, and so on.