While most developers don't hold interface designers in particularly high regard, honestly ask average people what they think of most developer-made interfaces and you'll find out the skill is a lot trickier than it seems. Most developers only think they know what developers do, but they're like many corporate workers see everyone from the head network architect to the community college desktop support intern as "computer people who can fix your email." Most think interface designers primarily work on aesthetics, but most probably aren't even invited to meetings about branding/visual aesthetic/etc...) Going further, many of those designers are savvy enough to write some basic code and likely bodge something into place, especially if they're using some kind of purpose-built interface that can handle things like data model consistency between builds.
It's a very unpopular opinion around here, but I think designers using the next generation of no-code tools will eat front-end and simple app developers' lunches and I think it will happen really soon. I'll bet teams at Wix, Webflow and other no-code authoring tools are working like mad to develop these tools right now, and I'll bet that's a hair's breadth from automatically generating electron apps from whatever users make there. If your specialty is code, and there are people with whole other useful skillsets that could passably approximate that capability with a few occasional hours from a contractor, the developer isn't going to be the one that still has a job.
While the demand for developers is still large, it's not infinite, and I look askance at assumptions that there won't be a really painful 'adjustment' for a lot of working professionals.