Olympus E-M1 Mk III>Macro
There are a variety of official first party and third party lenses. Micro Four Thirds has a slight disadvantage because at 1:1, the sensor being smaller means that you won't be able to fit a larger object in frame. That said, with the crop factor, the likes of the 60mm f/2.8 will have an equivalent focal length of 120mm. The Panasonic Leica 45mm f/2.8 also exists. If you desire, the Venus Optics Laowa 100mm f/2.8 also exists and can give you 2:1 macro. It is MF only though.>Nature/Wildlife
MFT is almost unrivaled in this area, particularly since the cameras and lenses are so much lighter, plus the E-M1 is weather sealed. The crop factor also means you need a much smaller lens to compete with an equivalent FF camera. The common go-to telephoto zoom lens is the Olympus 40-150mm f/2.8 Pro. It is weather sealed and is compatible with a 1.4x teleconverter that Olympus make if you want to boost reach.
The other options include a Panasonic Leica 200mm f/2.8 (which comes with a 1.4x tc in the box), but is seen more for its use in sports photography and the Olympus 300mm f/4, which is compatible with 1.4x, 1.6x and 2x tc.
The E-M1 has phase dectection which is used in hybrid with contrast AF meaning you don't get banding like on a DSLR.
All this plus IBIS that's basically unrivaled in capabilities and "Sync IS" with certain IS fitted Olympus lenses. Oh, and "Pro Capture", which takes up to 60 frames prior to shutter release and 60 after, allowing you to capture animals in motion.>Landscape
MFT's "failing" in having only 20mp sensors means that some people prefer a Sony FF for this. However, Olympus have a "high res" mode, which uses the IBIS to take multiple exposures and stiches it together. This allows for an effective 40mp handheld, and 50mp when tripod mounted.
Plus, Olympus make the 17mm f/1.8 prime, that's basically loved by everyone who uses it. Great for landscapes, travel and street photography.