What I don't understand is, with all the good tui frameworks/applications existing these days, how was Claude opus/sonnet/whatever not able to help anthropics e

What I don't understand is, with all the good tui frameworks/applications existing these days, how was Claude opus/sonnet/whatever not able to help anthropics engineer implement a normal approach ? I mean man, react before rasterizing ? Did any try that before ? That's clearly not what I would consider a good ad for their technology...