New elements are unlikely. We've already filled the periodic table for everything with 118 protons and below. As far as we can tell all the heavy elements are crazy unstable so its unlikely you could craft anything useful out of them. We haven't made anything over 100 that has a half life over a year so whatever you create will be extremely radioactive and change its properties very quickly

That said, new compounds/alloys/chemicals are found/created/designed fairly regularly. Alloys of steel with various quantities of nickel, chromium, molybdenum, and other metals are created all the time with slight to significant changes in the properties either making it harder or more flexible or more durable or better tensile strength or more corrosion resistance

There are a ton of different ways to create crystal structures out of atoms, we haven't created anywhere near most of them yet so there are still some oddballs out there with fun properties