. . . the show may close after only one performance if you don't have a strong supporting cast.
The flower can't carry the show all by itself.
The most important supporting actors are light and background.
If the light and background are not supporting the flower's performance, don't take the photograph.
In the above photograph, dappled sunlight adds to its impact.
Of course, if you're visiting the Sonoran desert for one day, and the light is so-so, you won't be able to come back when the light is superb.
So, yes, photograph the cactus in bloom.
Not every photograph has to be art, it can be a record, a memory.
Let's start with light.