Looks like they're going to kill it later this month. Today when I tried to use the HTML version, a splash screen loaded that said this: Starting from February

Looks like they're going to kill it later this month. Today when I tried to use the HTML version, a splash screen loaded that said this: Starting from February 2024, this version of Gmail (Basic HTML Gmail) will no longer be supported, and you'll automatically start using Standard Gmail. Switch to the latest Gmail version now.