New iPhone 13 and no charger box?!

Yes, it is completely the right thing to do. You already have probably a dozen or more USB power sources, and cables, all of which can be used to charge your new phone. See this Apple support article→About Apple USB power adapters for information on power sources for charging your Apple device.

Quoting that article:

As part of our efforts to reach our environmental goals, iPhone models no longer include a power adapter in the box. iPhone continues to work with existing power adapters and USB-A to Lightning cables, such as those included in prior models. iPhone models now include in the box a newer USB‑C to Lightning cable that supports fast charging and is compatible with USB‑C power adapters and computer ports that you might already have. You can use either a USB-A to Lightning cable or the newer USB-C to Lightning cable with your iPhone.

Fortunately, in addition to Apple many other technology companies have made the right environment move of not overloading the world with billions of redundant accessories that will eventually end up in landfills or poison the environment or the people who ultimately end up having to disassemble the devices that contain toxic components. Samsung and several other vendors also no longer include power sources with their phones and tablets.

The assumption is made that most users already have power adapters, computers, phones, adapters, hubs, car ports, etc.

As part of our efforts to reach our environmental goals, iPhone models no longer include a power adapter in the box. iPhone continues to work with existing power adapters and USB-A to Lightning cables, such as those included in prior models. iPhone models now include in the box a newer USB‑C to Lightning cable that supports fast charging and is compatible with USB‑C power adapters and computer ports that you might already have. You can use either a USB-A to Lightning cable or the newer USB-C to Lightning cable with your iPhone.

I personally have a home filled with different USB-A power adapters, some USB-C power adapters, plenty of MFi USB-A to Lightning cables, and even a few MFi USB-C to Lightning cables. The general idea is maybe the customer has or buys a few and has little need for more in the future unless they malfunction. The older USB-A power adapters can be slightly slower, but are perfectly fine to use.

I'd just note that this is on the "Buy" page with iPhones - at least purchasing in the United States:

Buy iPhone SE - Apple

As part of our efforts to reach our environmental goals, iPhone SE does not include a power adapter or EarPods. Included in the box is a USB‑C to Lightning cable that supports fast charging and is compatible with USB‑C power adapters and computer ports. 

We encourage you to re‑use your current power adapters and headphones that are compatible with this iPhone. But if you need any new Apple power adapters or headphones, they are available for purchase.

I suppose some will think that this is a cynical attempt to get customers to pay something that they would have otherwise gotten for "free" or at least included where it made little profit for Apple. However, I'd think that a good many will decide to go (with Apple's blessing) and purchase or repurpose non-Apple power adapters for use with their Apple devices. I personally think it's a win-win.

It's clearly noted in What's in the Box on Apple.com before you bought your phone. Since Apple never said a charging plug is included, it's perfectly fine to not include one. Just like Google and Samsung no longer include charging plugs with their cell phones.

If you've ever owned an iPhone before, you can use your previous charger with your new phone. Or you can use any USB C charging plug you may own for any other devices.

If you don't have any charging plugs which you can use, buy one. Or go wireless and not use any charging cable and plug. Your choice.