Framework choice is usually argued on syntax and settled on hiring. The costs that actually show up later are bundle size, build time, upgrade churn and hosting. Here is what each one costs and what it buys.
Minified and compressed, the runtime baselines are roughly: React with react-dom in the mid-40s of kilobytes, Vue around 34 KB, Preact under 5 KB, Svelte and Solid near zero because they compile away, and plain HTML at zero. Those are floors, not totals — a typical React app also ships a router, a data layer and a component library, and real-world first loads of 200-400 KB compressed are common. On a fast connection nobody notices. On a mid-range Android phone on mobile data, 300 KB of JavaScript costs roughly a second of parse and execute before anything is interactive, and that lands directly on your Interaction to Next Paint score.
Vite-based setups start a dev server in well under a second and rebuild on save near-instantly, because dev serves native ESM and only production bundles. Webpack-era projects with a large dependency graph routinely take 30-90 seconds for a cold production build and several seconds for hot reload. Over a year, a team of five saving 20 seconds per build across 40 builds a day is real money. Migrating an existing Webpack config to Vite is a day or two of work and is usually the highest-return performance task available.
This is the line item nobody forecasts. Framework major versions, meta-framework routing rewrites and rendering-model changes each cost days to weeks depending on app size. Ecosystems with a strong compatibility story (Vue's migration builds, Svelte's migration tooling) cost less than ones where the recommended pattern changes every couple of years. Pick partly on how much churn you can absorb: a small team maintaining ten apps should optimise for stability over novelty.
React has the largest candidate pool by a wide margin, which is a genuine business reason to pick it even when a smaller framework is technically better for the job. Svelte and Solid developers exist but hiring takes longer; on the other hand, both are easy enough that a competent React developer is productive in them within a week. Treat "we can hire for it" as a real advantage, and "our team already knows it" as a bigger one.
<form> that posts to a server has no hydration bugs.Static output can sit on an unmetered static host for nothing. Server-side rendering needs a running process or serverless function per request, and that is where the invoice appears — function invocations, cold starts, and egress. Choosing static rendering where you can is worth more on the bill than any framework choice.