It's more unified - in one place (in one function instead of two before).
It gives clearer log:

mode: no distortion, method: SOLVEPNP_IPPE -> Skip for non-planar object
mode: no distortion, method: SOLVEPNP_IPPE_SQUARE -> Skip for non-planar tag object

instead of

mode: no distortion, method: SOLVEPNP_IPPE -> 100% (maxErrT: -1, maxErrR: -1, meanErrT: -1, meanErrR: -1, medErrT: -1, medErrR: -1)
approximate translation threshold for 0.7: -1, approximate rotation threshold for 0.7: -1
mode: no distortion, method: SOLVEPNP_IPPE_SQUARE -> 100% (maxErrT: -1, maxErrR: -1, meanErrT: -1, meanErrR: -1, medErrT: -1, medErrR: -1)
approximate translation threshold for 0.7: -1, approximate rotation threshold for 0.7: -1

Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

• I agree to contribute to the project under Apache 2 License.
• To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
• The PR is proposed to the proper branch
• There is a reference to the original bug report and related work
• There is accuracy test, performance test and test data in opencv_extra repository, if applicable
  Patch to opencv_extra has the same branch name.
• The feature is well documented and sample code can be built with the project CMake