If there were ever any backdoor in some phone, it would have been found. No smartphone company is gonna take that chance that someone will find their backdoor, it will literally kill the company.
Or think of friends and family. When they become the target, you are prepared, you have the knowledge and tools ready, you can be the guide that helps them navigate a hostile digital world.
This is such a low-iq argument I cannot even. Yes, nobody cares about OP, you, me, whatever - until they do. Not to mention general harvesting for profiling and propaganda reasons.
General: What do people in this city/country/region/etc are thinking - This is the main one where the data is used and collected, then grouped. It is extremely powerful information for targeted agenda whichever it might be.
Targeted: Oh, you or someone from your close ones went to a political protest? Too bad we have all this information to put you and your family in jail - This is where suddenly they will care about you, even when it is NOT YOU but someone from your close circles were the ones upsetting them.
"While NSO Group markets Pegasus as a product for fighting crime and terrorism, governments around the world have routinely used the spyware to surveil journalists, lawyers, political dissidents, and human rights activists."[0]
Information these they can be much as powerful as a bomb, for example, I could learn more about your calls and discover that you do something immoral but not illegal and use it to blackmail you.
A recent court case investigating spying on 37 elected representatives [1] (including the prime minister, three ministers, and regional politicians) had to be closed in 2023 and again in 2026 “for lack of cooperation of the Israeli government”.
[1] https://www.rtve.es/noticias/20220510/pegasus-espiados-sanch... (spanish) [2] https://www.rtve.es/noticias/20260122/juez-archiva-caso-pega... (spanish)
And your second paragraph seems to go on the premise that the average person care if there is a backdoor.
I don't know why you wouldn't take security seriously, when even the US government is telling everyone to be careful where they supply their devices because of spying. Just don't trust them to point the finger the right way.
The US government is known to spy on anti ICE protestors.
If you have an opinion your government doesn't like, or a potential future government doesn't like, there's a good chance you have or will be spied on.
Perhaps you lack a single opinion worth caring about, but most people do not.
This is kind of like a mechanic not knowing what a car's exhaust does...