The serious difference is the hiring market
Svelte is genuinely pleasant: compile-time magic, less code, smaller bundles, excellent performance defaults. React is genuinely dominant: a hiring pool orders of magnitude deeper, an ecosystem for everything, and twenty years of Stack Overflow answers. Technical delight and operational safety are on opposite sides here, and buyers pay for both differently.
Svelte wins when
A senior developer or small team owns the product long-term (SvelteKit is a superb app framework), performance budgets are tight (embedded views, content sites, dashboards), or the product is a greenfield where the team wants modern ergonomics without meta-framework weight.
React wins when
Anyone might hire anyone (React developers are the default search result), the roadmap might need the frontier ecosystem, or organizational knowledge must survive staff changes, React's ubiquity is insurance. Most AI tooling, component libraries and specialist hires assume React first; that gravity is a real cost saver over a product's life.
Maintenance honesty
Svelte major versions have broken things (Svelte 5's runes migration being the recent one), with a smaller community, upgrades land on your team's shoulders. React upgrades churn too, but every problem has been solved by someone on the internet already, in public, with code.
The buyer verdict
Owner-operated product with a stable senior developer → Svelte is a legitimately great bet. Anything staffing-dependent, agency-dependent, or ecosystem-hungry → React, and enjoy the insurance. Both built here; the recommendation follows who will maintain it, tell me who that is.