As of Chrome 76, native lazy loading has come to the web!
Setting images in blog posts to
loading="lazy" (or user-configurable) could provide massive performance benefits, especially on blog posts with lots of images. The engineering team over at the BBC did a write-up about this and showed page load times reduced by 50%.
Wordpress is also looking to do this by default very soon as per https://core.trac.wordpress.org/ticket/44427.
Whilst this is only currently supported in Chrome, Safari has expressed interest, and Chrome does account for over 50% of the web.
This is a completely non-destructive and backwards-compatible change, so implementing it now will only mean further benefits in the future as other browser vendors implement the spec.