Some pretty amazing machinery in use in the video.
Mainly larger railroads could afford to have that equipment and not a short line.
I have seen CSX wooden tie replacement machine or machines being used near Indiantown FL, it undoes the spikes and pulls the tie out and inserts another wood tie and then can spike it as well. Another machine comes along and does the ballast.
Florida East Coast RR around Stuart FL used sections of pre-assembled track with concrete ties over eight feet long, don't know the size for sure, and then weld it in place.
Lee Fritz