Canon just announced the new Canon RF 10-20mm F4 L IS STM, the widest recti-linear full-frame lens. The new 10-20mm is a wider alternative to the RF 14-35mm F4L IS USM and it's closest alternative albeit in Canon EF mount is the Canon EF 11-24mm F4L USM. Below is a size, weight and specs comparison of these three lenses:
As seen on the picture, the new RF 10-20mm is impressively compact and lightweight compared to the EF mount 11-24mm F4, and almost same size ad weight as the RF 14-35mm F4.
Canon RF 14-35mm F4L IS USM vs Canon EF 11-24mm F4L USM vs Canon RF 10-20mm F4 L IS STM Specs and Feature Comparison