I'd say yeah, go mirrorless, but wait for Nikon's next entry if you want to stick with Nikon.
EVFs have been improving, battery life, while not on par with DSLRs, is pretty good on recent entries (I shoot for hours on the A7III, sure the A7II requires aggressive time-out, power-off to last, but can make it for a good number of shots), PDAF that goes across the entire frame without needing to hold the camera away from your face to use live view, smaller, lighter bodies, and most times adapters to use any lens you want. Video is a wash these days with the newer DSLRs having mirrorless functionality with their mirrors flipped up.
Even the new Canon DSLR works better in live view, their upcoming mirrorless is looking like a beast and they said they're not going to continue making DSLR lenses, so you can sort of see where this is going. Sony, Panasonic, Fuji are all on the mirrorless train. Nearly end of the line for DSLRs improvements.
Of course that doesn't mean you have to give them up.. People use film to this day. (I got a Rolleicord as a gift and I shoot that from time to time and if I have time to think, it's enjoyable)
I hope I made sense.