Bottom line is that you likely don’t need supplements if you are eating any reasonable variety of real food, and if you are not eating that reasonable variety then supplements won’t replace most of what you are missing.
The latter is both because the whole is more than the sum of the parts (being packaged for example inside plants cells surrounded by fiber matters to how it is delivered, absorbed, and the impacts it has), and because a variety of real food also has the unnamed cast of thousands of other substances of impact that no supplements have.
Most supplements have little (albeit non zero) potential harm other than in mega dosing contexts, but sometimes some people are more likely to allow themselves to eat more crap and less real food with the false rationalization that their multi or combinations of supplements is giving them insurance of getting what they need. And that is of real harm.