The VDB can also disappear because of the die being filled with debris/grease. What coins are missing the VDB? I haven't heard of them before.
Thanks for the link. Right there in the text it explains why these coins have the VDB missing. Yours isn't any different. The die wear that you see on your coin will progress further and further until the die is rendered useless.
The die wear on this coin is actually borderline ridiculous. It's got DDD on both liberty and the date and mint mark. The VDB is gone along with a chunk on that corner and Lincoln isn't nearly there anymore. The impression of the bottom half of Lincoln's bust is just a ghost of an impression and the top half is looking like Van Gogh and some other weirdness that goes almost all the way around below the rim of the coin. I've seen a TON of 2018D strikes and I'm pretty sure this is the worst one yet.