Really, this is very dependent on the kind of software you work in and what the focus of that software is. There's a wide world of software out there, with all different kinds of priorities and challenges.
That is included in what I said, many projects are fine with an MVP, that is why it is called MVP.
If your frontend is a game or some creator tool like photoshop then they will be complicated, but usually you don't call those frontends, and most frontend developers doesn't have the skills to make such products.
> Found the backend dev.
I've spent roughly equal time in both domains. Creating a frontend with the same quality as Google or Facebook isn't particularly hard (if you assume another guy did the UX design), it is tedious though. And that is basically all you have to be able to do to work as a frontend dev.
Most product teams for these companies have more frontend than backend devs. They’re building new features, sometimes multiple versions in parallel, fixing bugs and creating more of them, running experiments, and with modern frameworks, a whole lot of plumbing. You can basically generate infinite amounts of product work, and that’s what companies do.
I don't think so. Just see the progress of frameworks like react/angular etc. over the recent years. We also see concurrency being embraced more. There is still a lot of things to be improved in frontend, I wouldn't call that a solved problem, even though the problem space is narrower than backend/infra.