ItDontMeanAThing
Full time employment: Posting here.
Native mount lens selection varies by mount. Sony has the fewest. Micro four thirds (m43) has enough to satisfy most people except those who want high quality f2.8 zooms (some are available, more have been announced). Here are the currently available focal lengths (in FF equivalent):Disadvantages of the mirrorless are smaller lens selection (but I don't buy a lot of them so not really an issue), and shorter battery life.
Primes 16, 24, 28, 30, 34 (2), 35, 38, 40 (2), 50 (4), 60, 85 (2), 90, 120, 150, 600
Macro 90, 120
Wide Zoom 14-28, 18-36
Tele Zoom 70-200, 80-150, 90-150, 90-350, 90-400, 150-600, 200-600
Std Zooms ~24/28 to ~84/100 (many), 28-280, 28-300 (2)
Four thirds (4/3) lenses with adapters work with auto exposure and auto focus on m43 cameras. Olympus didn't sell many 4/3 cameras so few know about their pro quality glass.
Finally the video only camera makers and video optimized lens makers embraced m43. Everything is manual focus. About 20 prime lenses with FL between 15 and 100mm.