Congratulations, your noob user is now using JPEG-XL. It's not working on old devices, or any mainstream browser besides Safari. The less mature library also has a bug that allows for RCE and now everyone is running a cryptominer.
Now you say, but webp is supported everywhere, so let's go with that. Now the noob is using wepb for a bunch of rasterised vector graphics with 4 or 5 flat colors, and he's wasting more disk space than before.
So I repeat, if you need one size fits all, PNG is better, it works everywhere, and it's even more efficient in cases where lossless graphics matter the most.