So I have to purchase an adapter in order to charge my new iPhone 12pro?

No it does not.

Unless this is your first electronic device, you almost certainly already have a charger you can use with it. You can use any iPad, iPod or iPhone cable and charger you may own from the last 8 to 10 years. You can use a usb-c Mac charger from a MacBook, MacBook Air, and MacBook Pro made in the last few years, and you can use a usb charger from any Android phone or tablet made in the last 5 to 10 years with the correct Lightning to USB-A cable.

If you have absolutely no charger from any of these devices listed above which seems highly unlikely, then you will need to buy one.

No, and this was all over the news and other places. Samsung even made some commercials making fun of Apple. Until they also decided to do the same thing in the future. It is an environmental issue.

They also don't come with EarPods.

If you've ever owned an iPhone or another phone, you likely have a drawer full of charging bricks. Or maybe you moved over to wireless Qi charging as well? If you have none of these, then yes, you'll need to buy either a charging brick or a wireless charger.

I had no compatible charger and I have a few Apple products so I guess they weren’t current enough. Yeah sure, the new design does charge a little better, it’s little more efficient, but I would’ve been happy to not have had to shell out the extra money which was overpriced (of course) for what it is. Consider that every little tinker toy technology comes with wall adapters and or chargers. It’s ridiculous that we should have to do this! Everyone has already tacitly accepted not being provided with ear buds, somewhat reasonable, I suppose, but wall adaptors are such basic technology and so cheap to manufacture it just seems so chintzy on their part. This trend will continue so long as they are allowed to get away with it, which they seem to be accomplishing.

That's one way to look at it. But the vase majority of people who have owned smart phones over the years likely already have a drawer full of charging bricks. I certainly. And for iPhone I haven't charged with a wire and brick in over 3 years now as I moved to Qi Wireless charging long ago.

I'm sure some people needed to buy a brick, but I'm betting most people didn't need to.

It was widely publicized and shows on the Apple site for the iPhone.