He never claimed refterm was a fully working terminal ready to use. He said it was a renderer. The entire point of refterm was:

    <casey> Windows Terminal is slow at rendering things
    <microsoft> Yes, rendering is a hard problem worthy of a doctoral research project
    <casey> No it's not, you literally just use a glyph atlas
    <microsoft> You are naive
    <casey> *writes refterm to demonstrate glyph atlas*

You keep complaining that it's not a fully working terminal. Casey, on the other hand, writes:

"These features are not designed to be comprehensive, since this is only meant to be a reference renderer, not a complete terminal."

— https://github.com/cmuratori/refterm#feature-support