An icon served from an <img> is going to be served from browser cache (disk or even RAM) after the very first time it's encountered. Unless you're building some

An icon served from an <img> is going to be served from browser cache (disk or even RAM) after the very first time it's encountered. Unless you're building something designed to be used for one visit ever (maybe a promotional landing page?) it's better to have a few more requests (HTTP2 especially makes this a non-issue anyway) and have a cache full of assets than to make your dynamic webpages bloated.