Image SEO is worth the effort when images are a real traffic or discovery channel for your site, or when they materially affect page speed and user experience, and it is a low priority when images are purely decorative on a text-driven page. The pivot is simple: do the images drive value. Where they do, optimization earns its keep. Where they are filler beside the copy that actually ranks, deep image work is effort spent on something that was never going to move the needle.
Some sites live and die by their images. Recipe sites, product catalogs, photography and design portfolios, real estate, and visual niches pull genuine traffic through Google Images and image-rich results, and shoppers judge in seconds on a thumbnail. For these, descriptive filenames, accurate alt text, structured data where it applies, and properly sized files are direct contributors to discovery and conversion. Optimizing them is not housekeeping; it is working a real channel.
The other axis is performance. Even on a text-driven site, oversized or unoptimized images are one of the most common drags on load speed, and speed and visual stability feed both ranking signals and user experience. So compressing, sizing, and serving images efficiently is worth it almost everywhere, because that benefit is about the page being fast, not about the image ranking. What is usually not worth deep attention is the discovery layer for decorative stock photos and icons on an article whose value is its text. Those need correct alt text for accessibility and sensible file sizes, and little beyond that.
Look at where your images sit. If they are a discovery channel or your buyers decide on them, invest fully in image SEO and treat it as a traffic source. If they support text that does the ranking, keep to the basics, compress for speed and write honest alt text, and put your effort into the content and structure that actually earns the visits.