You get the exact same quality at around ~25% smaller than other image formats. Unfortunate that it’s not supported by everything, but yeah it’s a better image format practically in that sense.
On the web this saves money when storing at a large scale, and it can have a significant impact on page speed when loading websites on slower connections.
I'd rather see the savings in the army of Javascript I apparently need today for the 'modern' web experience. Image files have gotten lots of love, but hey, here's a shitty 27 year old language designed for validating form input!
There are more places where bandwidth is a bottleneck now than 10 years ago.
NIC speeds have gone from 100Gbps to 800Gbps in the last few years while PCIe and DRAM speeds have nowhere increased that much. No way are you going to push all that data through to the CPU on time. Bandwidth is the bottleneck these days and will continue to be a huge issue for the foreseeable future.