Does charging my phone in the car really drain the battery when engine is off?

[simregistration]

I have a quick question about something I do all the time and I'm wondering if I'm slowly killing my car battery without realizing it. I have a 2015 Toyota Camry and I often sit in my car during lunch breaks or while waiting to pick up my kids. I usually plug my phone into the USB port to charge it, and I listen to music through the car's speakers with the engine off. Sometimes I do this for 30 or 40 minutes. A coworker saw me doing this yesterday and told me that I'm damaging my battery, especially in the summer heat. He said that the USB port and the radio draw power from the battery, and if the engine isn't running, the alternator isn't recharging it. He told me to check this guide about battery drain in Sharjah to understand why this is bad. My car still starts fine, but I have noticed that on days when I charged my phone for a long time, the engine cranks just a tiny bit slower when I finally started it. Am I imagining that or is it real? How much power does a phone charger and the radio actually use? Could 30 minutes of radio and phone charging really drain a healthy battery enough to cause damage? What about using the USB port just for charging without the radio on is that better or the same? I've also seen people use those cigarette lighter chargers that plug into the 12V outlet. Do those draw more power than the built in USB ports? I don't want to stop using my car during breaks because it's comfortable, but I also don't want to get stranded with a dead battery or have to replace my battery every year. Is it safe to do this if I run the engine for a few minutes every 20 minutes to recharge? How long would I need to run the engine to replace what I used? Any advice from people who understand how much power these things actually use would be really helpful. I'm not a car expert so please explain in simple terms. Should I stop doing this completely during summer, or am I worrying too much about a small thing? Please share what you do in your own car.