Also, we don't know what kind of server resources they use vs. HN. The initial weight of SPA is typically much more than "plain html" site, but that's the price

Also, we don't know what kind of server resources they use vs. HN. The initial weight of SPA is typically much more than "plain html" site, but that's the price you pay for client-side functionality. Also, there exist more lightweight alternatives for React, e.g. Preact.