Întrebare [is MKV supported?]

For that matter, none of the other big-name NLEs support MKV at all.

You see, when Premiere and its big-name competitors were developed, most video that these programs were designed for was done on uncompressed footage that was done in huge, truck-sized cameras. Compressed small-cam video was rather begrudgingly added on over the years.

MKV is NOT supported
-https://community.adobe.com/t5/premiere-pro/converting-mkv-files/td-p/10610163?page=1
-VLC https://community.adobe.com/t5/Premiere-Pro/Simple-lossless-conversion-of-mkv-files-Matroska-to-mp4/td-p/8785670
-and another https://community.adobe.com/t5/Premiere-Pro/Importing-MVK-files-into-Premiere-Pro-all-versions/td-p/4943577