You can use older power adapters with the older cable when charging can iPhone 14. Apple encourages it. See the following from Buy iPhone 14 and iPhone 14 Plus - Apple
As part of our efforts to reach carbon neutrality by 2030, iPhone 14 and iPhone 14 Plus do 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 USB‑A to Lightning cables, power adapters, and headphones, which are compatible with these iPhone models. But if you need any new Apple power adapters or headphones, they are available for purchase.
However, if you want to fast charge you will need to use an 18 watt or larger USB-C power adapter. See: Fast charge your iPhone - Apple Support