My lumber yard lets me pick : ) I pass on 50% of the lumber in the stack.
Even what I get isn't 100% perfect, so I sometimes will surface 4/4 or 3/4
S3S to a slightly smaller dimenson. It all depends on what I'm building.

My point was mo Pick your rough stock for a project, and have the yard
thickness it and joint one edge. If you get joy out of making rough ones
into smooth ones, by all means have at it. I have a stockpile of rough
lumber that I bought because the price was right. I'll mill it when I know
what I want to do with it.

I'm with Dave on this one. It's not about the joy. If I did have my supplier
surface my stock it might be weeks before I could mill and assemble all the
pieces (YMMD). It also would not give me the opportunity for stock to
acclimate to my shop conditions.

You just have better quality control (for straight and flat) when you do it
yourself when you need it.

Your way is efficient and is probably perfectly adequate, but in-house
dressing of lumber is likely to yeild flatter stock most of the time.

-Steve