Battery life is better on DSLRs.
In general, mirrorless has gone with EVFs. Some people may still prefer optical viewfinders.
Lens selection is still better, and lenses are cheaper. Lots of options on the used market.
And you can get a pro body less expensive than a mirrorless pro body.
Get the tumbler and media. If dirty primer pockets worry you, use a primer pocket uniformer. Personally, I don't care. Reloading is not a cheap hobby. Going to have to drop some coin eventually.