I think it has a bigger impact than you realize. The last iPhone I owned was the 3GS. I don't particularly like iPhone or Android; I'm hardly a fan boy. But, I'm seriously looking a iPhone 15 variant as my next phone.
I have USB-C for virtually everything and have no interest in dealing with keeping a second set of cables for one device. It's an extra expense, headache, and environmental waste I don't want. The change to USB-C makes an iPhone a viable option for me. I look forward to a refreshed SE line with USB-C as well.
I'm not thrilled about all the cables and dongles/adapters eventually going to landfills, but believe the move will be better in the long-run. I wish Apple made the move earlier.