The main reasons I do not like tea is that many substances are heat sensitive and water does not extract everything. So powder is a much better choice.
In most cases I prefer getting nutrition from plants. There are some cases though where isolated supplements are needed. For example, when extra magnesium is needed to counter calcium in order to lower blood pressure or to stop muscle spasms. In these cases I prefer the acidified or chelated forms. I do not like the oxides, hydroxides, or carbonates as these are poorly absorbed and can cause a variety of health problems.