Maybe. Probably. Sometimes.
It’s clear that the third-party makers have offerings that fill in many, if not most, of the gaps in Nikon's own lens lineup. The question then becomes whether those lenses are up to the level of the Nikkors.
I'm going to do a lot of generalizing here, so be careful of over interpreting my remarks.
Let me first take this topic on by cost. In general, at the lowest cost points, I've found the Nikkors to be almost universally significantly better than the third-party lenses in my testing, though the gap in performance has lowered over the years. The current 18-55mm Nikkor AF-P VR essentially sells for US$99 when you buy it with a body. That performance and price point is hard to top: the 18-55mm Nikkor AF-P VR is a very good lens, has little sample variation in my experience (I've now tested four), and comes at a pretty unbelievable price. What I've seen in the low-cost third party lenses is poorer corner performance and chromatic aberration control, poorer quality control, and prices that really don't undercut Nikon.
Now let's take this by brand. Sigma tends to produce very sharp lenses, but seems to have somewhat erratic quality control. I've gotten several "bad samples" of Sigma lenses over the past decade. But the good samples tended to test very, very well. Just make sure you know how to test for bad samples and have a good return policy from your dealer if you buy Sigma.
Tamron seems to be fairly consistent on quality control, much like Nikon. I've rarely encountered a bad sample of a Tamron lens, though I have encountered bad reverse engineering (their 28-300mm caused Dead Battery Syndrome on my D700). Again, Tamrons are fairly sharp lenses in most of my recent tests. But one thing I've noticed recently is that Tamron hasn't perfected the in-lens motor. Many of the in-lens motor versions of Tamron lenses autofocus more slowly and/or more noisily than the screw-drive versions. On the flip side, Tamron's optical stabilization seems better than those on some Nikkor's.
Tokina lenses have a reputation as being very sharp. Indeed, every one I've tested has been. But I've also had a lot of flare issues with Tokina lenses, enough that I tend to avoid them when I have a different choice. All that said, if a third party maker has a lens variation that Nikon doesn't and you need that, don't be afraid to try them.
