Loss of quality : smooth edges in png are serrated (or saw-edged) in exported video

Hello everyone,

I have a question concerning the quality of the exported files in Premiere Elements 19. I have been using Premiere Elements for several months and am generally quite satisfied with this program; it is not too complex to use and it still has some possibilities in terms of video editing. People who want more will probably switch to Premiere Pro. But this package has a different cost.

I am less satisfied with the quality of the exported files. But I'm convinced that it's up to me and that a few parameters need to be set correctly in order to achieve a good result. I have read related conversations on this topic within the Adobe community, but have not found the right solution yet. Below or in the appendix, it becomes clear what I mean. I made a drawing in Fusion 360 and made a render of it. The size of the render (or image) in png format is 1920 x 1080 pixels. If I try to make a clip out of this image and export it as mp4 -H.264 file in HD 1080 (or 1920 x 1080), with a frame rate of 29.97 and in the highest quality, I get visible quality loss. On the render you can see for example flowing white lines, on the video those lines are serrated (or saw-edged). What can I do to fix this? I've already changed a lot of import and export parameters, but still without results. All tips are welcome to get this right.

Thanks in advance.