For everything else, it’s easy to either generate webp alternates to jpeg/png and use a picture element (for non-responsive srcset, only three inner elements are required for this), or to use Cloudflare or an image CDN that automatically serves webp. Usually a project that requires a framework or SaaS that can’t easily support one can use the other.
As others have said: if the bulk of your traffic is people using the latest hardware, then polyfills are probably overkill. If you need to cater for more niche target audience using legacy hardware, then by all means, use polyfills.
Not joking, either.