Compare this: (https://www.questionablecontent.net/view.php?comic=3) to this version of the same strip, drawn much later: (https://www.questionablecontent.net/view.php?comic=1601). That’s the same artist. There was no abrupt change in style, either, the artist’s style just slowly changed over time.

Almost as large an improvement can be seen by comparing this first strip: (https://www.schlockmercenary.com/2000-06-12) with the same strip, redrawn much later: (https://www.schlockmercenary.com/2020-07-27). Same thing there; same artist, no abrupt change in style, just slow improvements over time.