Teams often begin with the question of which framework is "best for SEO." That framing is too broad. For a public application, the first evidence to collect is whether search engines can discover each intended URL, retrieve a useful response, render the primary content, understand the preferred canonical version, and follow ordinary internal links to deeper routes.
The linked AngularJS SEO FAQ covers the underlying rendering questions in more detail. For this comparison, use the same test on every candidate architecture: inspect the initial HTML response, compare it with the hydrated or browser-rendered page, and verify that essential content and metadata remain consistent.
Server-side rendering can place route-specific HTML in the response. Static generation can publish route-specific HTML ahead of requests. Prerendering can create rendered output for known routes. Client-side rendering can still be indexable, but it creates more dependence on successful JavaScript execution and therefore deserves direct validation rather than assumptions.
The decision point for a web design agency is operational: which approach can the team implement correctly for the application's public route types, keep synchronized with user-facing content, and maintain as the product changes? A framework with convenient tooling can reduce implementation friction, but the final SEO result still depends on the delivered pages.