A penny for your thoughts!
The late great Richard Feynman always maintained that genre labels aren’t really that important, and that there are as many definitions of science fiction as there are writers on the topic, including ‘what science fiction authors write’.
One more or less approximate definition of SF might be to call it fiction where the protagonists' story is influenced or shaped by science or technology.
Lab lit? (Coined by Jenny Rohn, a lab scientist in the UK) Well, some of it is science fiction, some of it is a perfectly ordinary love story or mystery story or whatever that just happens to be set in a lab (at least, that’s what Dr. Rohn maintains).
Some say that ''anthropogenic climate change stories'' date back at least tothe BBC series from the 1970s titled "Doomwatch" -- WIKI HERE -- and there might be older examples, too. [PLEASE TELL ME!] Why? Because they portray the result of the impact of science/technology on the lives of the protagonists and therefore there is not any reason not to consider them science fiction.
Of course, if one takes something like L. Frank Baum's "The Wizard of Oz,'' where the climate plays a significant role but there is no science or technology involved, nobody in their right (or left) mind would class it as science fiction. But could Baum's tale by classified as cli-fi? No way.
So there you have it: Do genre labels matter? Yes and no. They play a role in literary discussions. But basically, they are just "signposts along the way." Cli-fi, too. Skiffy, too.