Actors don't like to stick around on one show for a long time (usually), so let's have a look at why the actors who played classic companions left the show. / discord / thewholook
I saw they posted a similar video to my Doctor actors quitting one a few days after mine and I saw they claimed it was a coincidence and they hadn't stolen but that's as far as I know, I'm sure it probably was a coincidence though.
Adric wasn't written out due to the actor deciding to leave but instead the producers or something like that going we have too many companions & we need to cull them a bit to fix our scripts so that we don't have a small amount of people doing nothing each episode. They killed him & from Earthshocks audio commentary the female actress of Nyssa teased him about leaving at the time.
It’s probably been mentioned already, but your list of returning characters completely omits the five doctors. Susan, jamie, k-9, zoe, sarah jane and the brigadier are all featured, as is romana via unused footage from shada. It’s a trivial point, but I found it irritating when it came up. Similarly you missed a few companion returns from the dimensions in time charity episode. I’d need to check imdb, as I’m not 100% sure which ones.
Yeah I wanted to mention some returns but I didn’t want to focus on every return as the focus was departure from main roles and mention a few who would return for other appearances. Maybe I should have mentioned everyone’s returns though
I saw they posted a similar video to my Doctor actors quitting one a few days after mine and I saw they claimed it was a coincidence and they hadn't stolen but that's as far as I know, I'm sure it probably was a coincidence though.