the funny thing is ... it is just as true 130 years ago as it is today
usually you can't get commissioned work without a portfolio of work
to show that you can do more than draw or photograph or whatever ...
and you can't get the commissioned work without having experience doing it ...

as a photographer seeking freelance employment, perspective employers don't really care about
personal work, although it does make for interesting conversations, they want to know who you worked for
did the work get finished on time and was done as expected, they want to see "tear sheets" ...

what FLW did was lie about his portfolio, he said he designed houses for people he never did
and the people who hired him didn't bother to contact his previous "clients" to see if he was FOS ...

he got the commission, and the rest was history.

as scott said, there is a lot of difference between doing renderings and line drawings and actually building something that exists ...

i always got a chuckle out of the emblem for " the school of mines " (architecture school before it was called architecture school)
it is a golden shovel ... and, it suited frank lloyd wright well