And where exactly did I say that my statement is a fact and not an opinion ?

Hint:

is an expression on an opinion. The dude abides on that....

Early 1980s based at Fields aviation LHR South side flying new Citation 2s (4 new '2s and 2 older '1s). Had dispensation to reposition said aircraft from e.g. Luton, Gatwick, Biggin Hill single pilot. I did it many times but always found a friend to sit in the right seat! Don't remember it as being overly arduous.

Another opinion, I would say (having done it) that operating a light jet on a short and presumably low level sector single crew isn’t a problem. It’s easier than doing it in an MEP, if an engine stops there’s only one lever, less yaw with tail mounted engines, more thrust and better climb if you have an engine failure on take-off. And if you need more time you can slow it down.

Long sectors, high altitude. How about an explosive decompression at FL400? Two crew, if one of you doesn’t get your mask on quick enough at least the other one is still able to descend and keep everyone alive. Single crew and that might be a problem….