Oh I would never be on board with someone else playing my player character. Not to mention my characters are generally extremely complex and playing them is difficult if you don't understand how they are put together.
I've experienced this before, both as a player and as a DM. Sometimes it's OK, but at other times, it doesn't end well.
With my "home" group, my players currently consist of my teenage daughter, my wife, and another couple who are friends of ours. They've only ever played 5e (since 2014 for the adults), and we did briefly try playing with a missing player once or twice, but then the husband got his wife's PC killed once. She brought it up just last night, so I'm not sure she's forgiven him! These days, we cancel or reschedule if even one player can't make it.
With my other group, which is currently on hiatus, the players are all in their 50s+ and have been playing since the early days. They're much more stoic about things. "I can't make it, but the show must go on, so play without me and someone else can control my PC." I
have instituted a rule whereby a PC can't actually die while being controlled by another player. If they get reduced to 0 hp, they automatically stabilize and the monsters just ignore them. If the whole party gets wiped, that PC might miraculously survive to escape and gather a new party to avenge the other party. I have occasionally run sessions with just two players, but my preference is to only run a game with a minimum of three players. (While I have had as many as six players at times in the past, my preference as a DM is for 3-4 players.)