Media Encoder can convert 24fps video to 30fps video. Impressive, but how?

This is a traditional film-to-video process called a 3:2 Pulldown, where frames are processed to fill up the same amount of time at the higher framerate. If you want to learn more of the technical details, take a look at https://www.extron.com/article/32pulldown

AME can come up with new frames, but it depends on your Frame Interpolation settings:

The avilable settings are:

Frame Sampling: Frames are duplicated on an even interval to fill up the frame difference. Tends to be the safest setting with only slight frame jitter introduced.

Frame Blending: Frames are time-stretched out and faded together. Movement may be smoother but at higher frame rate conversions can look fuzzy.

Optical Flow: Creates new frames in a process similar to Photoshop's Content Aware tools, where tween-frames are generated. Works best for slow-motion or other footage where there's less change frame-to-frame. Can badly morph footage that has quick movement, and is more render intensive. If you're interested, check out https://theblog.adobe.com/optical-flow-time-remapping-tips-tricks-for-best-results/

I'd recommend trying samples with different settings to see what works best for individual cases, but I usually stick with the default Frame Sampling because the visual difference, as you've found, is minor and less distracting.