I bid farewell to DX when Nikon didn't come out with a D300 replacement for so long. I had saved $$ for it, but I ended up spending it on a dive housing for my D810 before the D500 finally came out.
I don't miss DX. The gear wasn't particularly lighter than FX except for the widest angles. (loved the 10.5!) And before you say 'but a 300mm effectively becomes a 450mm', no, it's not. It's just a cropped 300mm, and I do that on my FX 45mp cameras too.
It’s fine if you prefer a single 45MP FX camera. You can still do that, including cropping, even in the light of existence of 24MP FX and 20/24MP DX cameras.
I get about 20mp from a DX crop. I rarely crop to DX format, but I crop most of my shots from a little around the edges to 'this is only going to the web'.
Some people might prefer two bodies, one FX and one DX, which are cheaper per body.
I have to wonder why. Myself, I've long shot with two bodies. (Since about 1994 when I added a Nikon N90s to my N8008s). With two similar bodies, I used to alternate film types mostly, putting ISO 25 to 100 in one body and fast film (ISO 400) in the other.
As soon as I had multiple digital cameras, I hung one (D70s) over one shoulder and the other (D200) over the other. Each time I upgraded cameras I demoted one to the second shoulder and shelved the oldest camera.
Then came my D300 and D700 experience. At this time I also shot a fair amount of CX format with a V1 and a V2. I used the crop cameras for wildlife and the D700 for everything else. All the cameras were about 12mp. I sometimes carried the D300 into the field with an 80-400 mounted and the D700 with a 105macro for things I'd find on the ground. But basically I never got along with mixing a DX and an FX camera at the same time. Lens transitions just didn't make sense.