Coding agents have actually cut both ways for me. I can reinvent the wheel more easily and with higher quality, but I can also integrate an external library much more easily than before.
The other day I needed my system to download SFTP, so I had the agent build an SFTP client. It turned out that I actually needed FTPS, so I had the agent build that too.
Another time I wanted to integrate with Git repos, but instead of trying to reinvent that, I asked the agent to integrate libgit2. Of course, I asked it to add an API that matched the semantics of my system, so from my perspective, the wheel was exactly how I wanted it.
I think what's going to happen is that there will be more vertically integrated platforms that do it all. If you think about it, it's really annoying to cobble together a system from different libraries, each of which might have different semantics.
What we want, as developers, is to have a single, well-designed, integrated platform that exposes all the functionality we need in a consistent way. That's a lot easier now that LLMs can mold code to your exact specifications.
I'm biased, of course, because that's exactly what I'm building with GridWhale.