No one has claimed you would have to pay for open/free software. But, as with everything else, you need to calculate the total cost of ownership. And there your personal effort or your efficiency comes into play.

Yes but having choices doesn't take time, only using them does. Picking one OS over the other because of many options is basically saying "I can't have choices because I can't stop myself from using them". What takes time is having an OS you have to fight because it refuses to do what you need it to do because of some decision taken by Apple. When that happens MacOS gets extremely expensive in time.