Question

Everything in the world is renewable then why do we need conserve resources

Answer 1

not every thing in this world are renewable on the other hand different things take different time to regain itself like Fossil fuel regian after thousands of years while plant regain in few years ..

Answer 2

Yes it's true that matter and energy both can't be destroyed but the fact is that it gets converted in any other form and that form (for us) is not harness able or useable and takes a lot of time to convert into their useable form.

Thus to avoid all the energy get converted into un-harness-able energy, we need to conserve it.