The conclusion of "yes, Claude helped fix this, but it also caused it by recommending an emoji font" seems a bit disingenuous to me. Using an emoji font is a good suggestion, it's not like Claude (or anyone) could have known there's an SVG but that will cause this slowness.
Still, I'm going to quote the living daylights out of "These coding agents are very much like a power saw. Profoundly useful, and proportionately dangerous."
Even though this particular case may not be fair, the comparison feels like a very fair one to me. The notion that these things can be very valuable in capable hands, but costly in others.