To improve my websites' user experience, I want to optimize site speed, as well as search engine ranking.
Google stated that Improving web speed can benefit ranking in search engine results, but apart from that, search engine optimization seems hard to measure. Most search engine optimization advice seems to be rather anecdotal than based on facts and measurements.
Following advice in a Lighthouse web page speed report, I started to "use a Content Delivery Network (CDN)" by deploying to Netlify. As I understand, content delivery networks help to reduce connection and transfer time by providing content from a nearby mirror server. Many also offer automated image optimization, reducing file size.
Deploying a website on Netlify with the asset optimization feature activated, images are automatically hosted on a CDN, rewriting image URLs to CloudFront subdomains instead of the original website domain.
During talks and discussions, web developers and search engine optimization professionals claimed that using CDN domains will harm efforts to make a website's images rank high in image search results. But they could not cite factual information to prove their claim.
As discussed earlier on StackOverflow, providing redirects to the new URLs should prevent a temporary drop from image search results.
It is not clear to me if there might be any other disadvantage of hosting images on a CDN. I asked the google community how to ensure image search optimization when hosting on a content delivery network, but I did not get an official statement from Google so far.
Please help me to solve this dilemma based on facts and evidence.