Mirrorless is such a great thing. A new mount is created in order the make the camera body slim. Then, an adapter (not free) should be added to make the body as thick as a DSLR in order to be able to mount your existing lenses. Wow, that's so smart. No, that's innovation!
With your DSLR you had 1000 shots battery life without grip, now you got a thrid of that, you need to buy a grip just to get back to your old DSLR battery life. What the heck? No, that's innovation led by Sony!
When you swapped lenses on your DSLR the mirror got the dust and any dust that made it through the mirror got stopped by the shutter that is normally closed on a DSLR, now with your new mirrorless when you change a lens, the sensor will be directly exposed less than 20mm behind the mount, you'll get dust spots on the sensor more often, don't forget to buy a sensor cleaning kit (in addition to of the mount adapter and the battery grip with 4 batteries). That's innovation. When you had your DSLR, the lenses where designed to work with the AF of your DSLR, now your mirrorless camera AF will eventually hunt fail to focus with the old glass, so you'll have to buy new lenses for the mirrorless camera (for using the lenses without the adapter). Go mirrorless you are back to square one with the system, you are good to scrap your dozen of lenses hard earned over the last decade, and now you have to start all over again... that's innovation.