Depends on the objective. In some cases, slapping together a few components is fine and straightforward. In particular if you pay attention to how other people

Depends on the objective. In some cases, slapping together a few components is fine and straightforward. In particular if you pay attention to how other people are using them - perhaps pay attention to the provided standard schematic and layout in the spec or application note - and if you are well within the expected use for these components. Notice magazine articles. Use several sources. Something might still go wrong, but then you might also buy the wrong widget from the wrong seller... If you are deliberately striving to push the limits one way or the other, then yeah, you will run into the exact reasons nobody else did it.