Creating a flawless or nearly flawless deepfake video takes a lot of work, like using a large set of images, training the model a lot, fine-tuning, and a considerable amount of effort. DeepFaceLab is a tool that's good at making top-notch deepfake videos, but it's not easy to use, it needs time, effort, and tech skills. Some tools that give okay results (not perfect, especially when the face is at an angle or blocked) just need one face image. It's much easier to use but sacrifices some quality. This represents a trade-off between convenience and quality.
For making deepfake videos, besides the suggestions mentioned, check out vidfaceswap.com. The results might not be perfect, but they're quite satisfying. One tip is to only upload the video part where the face is clear and skip the bits where it's at an angle or covered by stuff.