Even for basic sites, I tend to reach for an SPA because I never know when I'll be adding dynamic features, anything from basic showing / hiding of content, list / configuration-based rendering, or requesting data.
It's usually inevitable, so it's easier to scaffold a Vite template and get cracking without any additional setup. The time-to-deploy is fast using something like Netlify or Vercel, and then I have the peace of mind knowing I can add additional routes or features in a consistent, predictable way that fits the framework's patterns.
I'd hate to develop an MPA and realize after the fact that now I need complex, shared data across routes and for the UX to be less disrupted by page loads. Once you've dug that hole, you either have to live with it, or face a painful rewrite later.
The exception I often see is targeting mobile devices in low-bandwidth areas where larger application bundles take longer to load, but I have to wonder how often this is the target audience. I live in a place where mobile data speeds are horrible, and access to WiFi is abundant, but even so, I rarely have a situation where I *need* to load up a non-critical site on the go — and having apps pre-installed doesn't really help either when the data they're requesting is barely trickling in on mobile.
So this oft-used exception doesn't really make sense to me unless I learned why this is so critical for some people.