The term “full frame” has become extremely popular within the mirrorless sector, starting with the release of the Sony A7 and A7R in late 2013. Leica followed a few years later but it was really between 2018 and 2019 that the segment took off, with Nikon, Canon, Panasonic and Sigma all hopping on the bandwagon, racing to grow their respective systems as quickly as possible.
Because of this, there is an awful lot of choice in the full-frame mirrorless range these days. If you’re already acquainted with one or more of the brands, it might be easier to choose between them, but otherwise selection can be overwhelming.