For my photography (mostly wide field astro and weather) the DSLR still has significant advantages. One of them is battery life. I typically shoot 1000+ photos on each shoot and it is just easier to not think about when the battery will be empty and needed to be replaced.
DSLR battery lifetime is frame based, mirrorless is time based.
With DSLR you get X frames per battery, but you can keep camera powered for hours/days with little penalty to battery if you are not taking photos.
With mirrorless you get X hours per battery, you can keep camera powered those hours with little to no penalty of you are taking photos.
With mirrorless you look your watch, you sum the event time to how many batteries you need for constant power time.
A hockey game takes that 3x20min and middle periods, so you can shoot whole event work a single mirrorless battery as typically they offer 3-4 hours power time. And you can get thousands of frames with a single battery, basically your memory card is the limit for 3-4 hour period with one battery. A wedding of typical 4-7 hours you do with two batteries or two bodies. And again possible get thousands of frames.
That is nice thing with mirrorless that you know before that when battery will go empty as you have (depending model) the 3-4 hours without sleep mode.