Constance Burge ran (https://thecharmedcafe.proboards.com/thread/11867/best-showrunner) the first two seasons and then Brad Kern took over in Season 3. The seasons with Burge (https://thecharmedcafe.proboards.com/thread/10816/connie-burges-charmed) were basically monster of the week (https://charmed.fandom.com/wiki/Constance_M._Burge) storylines. It was Kern (https://thecharmedcafe.proboards.com/thread/8751/who-brad-kern?page=2) who added season long arcs and ongoing storylines. Apparently, Shannen Doherty (https://thecharmedcafe.proboards.com/thread/9862/shannen-doherty-on-charmed-experience) was not happy with the latter direction. And once she left (https://charmed-snark.livejournal.com/25899.html) along with Burge (https://thecharmedcafe.proboards.com/thread/12454/constance-burges-intent-charmeds-direction), the show (https://thecharmedcafe.proboards.com/thread/11548/brad-kern-wb) more or less, became a supernatural soap.