I don’t know if Hugo has become ‘too complex’, but it has for sure become more complex in the last year(s).
The last release (0.78.0) even added "js.Build fully supports the virtual union filesystem in Hugo Modules.", which is a short sentence with three terms that I don’t understand. 
But I don’t know if this is a problem. For people that need complex features it’s probably quite useful. And for me it makes no difference since I don’t use those features.
I am worried though about the experience for new users. Beginners that run into issues with a theme have a hard time troubleshooting (which is also the fault of theme creators for adding complexity). Learning Hugo is not easy because there’s a lot of material to go through.
Several weeks ago I read a Hacker News discussion that had love for Hugo, but also people that even hated working with Hugo. Most of the complaints were about the template language and the complexity, or a combination of both.
A couple months ago we also had the JAMStack survey. While there were valid concerns about the sample demographics, it showed that Hugo users that participated in the survey weren’t as satisfied as Svelte, Nuxt, Next, 11ty, Vue, Gatsby, or React users.
If the Hugo team would be bigger, it would be awesome if we could have something like Go’s developer surveys to learn what pain points there are.
But from what I understand most of the Hugo work is already done by only a few individuals in their free time. So while I agree that parts of Hugo are too complex, I don’t see a solution without asking for even more from the people that already gave us so much.