Managed to get my website out of the top third and into the bottom third of the resource-intensity index on https://www.websitecarbon.com through more thoughtful media compression/resolution choices and with very little noticeable loss in fidelity. Also checked with my provider whether they host climate-neutral (they do), as they are not listed on https://www.thegreenwebfoundation.org/.

https://media.ccc.de/v/36c3-10506-the_planet_friendly_web (german, english dub available) is a great primer on the topic, https://branch.climateaction.tech/ also has some really great articles on this, e.g. https://branch.climateaction.tech/2020/10/05/10-rules-for-building-a-low-impact-website/.

Most of what I present on my website is by nature (and probably will continue to be) audiovisual, so I will always have to make compromises (and there's still so much more to explore in how to creatively approach this), but regardless, a two-thirds reduction of data transferred even under these constraints shows that we all can make drastic changes if we put it on the agenda. For me this was quite an encouraging undertaking and result.