I don't think so, companions tend to be unknowns so what else do they have to do? The exceptions were Rose who was a 90s pop star, Donna who was a comedian with her own show and Graham who is a quiz show host.
Yaz was in a daily soap opera for 3 years 2012-2015, probably the least watched British one. She's had a handful of guest appearances on other soap operas since then according to Wikipedia. Her career is over.
Ryan was in the same soap opera from 2011-2012 and has had bit parts on TV and Movies since. His career is going nowhere. I don't know how they paid the bills doing nothing for so long.
Graham did some stuff before but I know him from being in the largest daily soap opera for 2 years and transitioning into his quiz show hosting which is still on TV after 11 years. He is going to be just fine, his own show is only a million behind Dr Who in the ratings now and it's on several times a week haha
Maybe Karen Gillian chose to leave to be a multi billion grossing Hollywood actress? I can't think of any other companion who has done anything higher profile than Dr Who. There's been a few sideways moves like Clara playing Queen Victoria in a multi season drama and John Barrowman doing some presenting. The actress who played Bill probably isn't getting much work