Cable channel numbers are a bit messy as there was no real standard, and they often go back decades. Comcast does have standardized numbering in the 1000's and are roughly categorized:
1000-1199: Local channels (numbers will vary from city to city), news, weather
1400-1599: General cable networks
1750-1899: Movies, premium networks
Numbers below 100 will vary from city to city as it dates back to the analog era when different towns may have had different providers. 101-999 will often be the same within regions as it came during the digital rollout in the early 2000's. (Example: in most of the Chicago area, WFLD-HD is 190, but WFLD-SD can be 3, 12, or possibly others.) Even 100-999 are often roughly categorized in many areas, but became a bit of a mess when networks changed formats over the years (FXX used to be some sports network.)
So why not just change them? People still tend to think of channels and networks by their numbers, and changing that can cause MAJOR outrage.