The ATtiny814 is hardly an ancient chip. It's a member of Microchip's TinyAVR 1-Series that was released in 2017 and still being developed, with the 2-Series being released in 2020/2021.
Perhaps you're confusing it with the older ATtiny841 (released in 2012), which was an upgrade of the original ATtiny84.
Perhaps you're confusing it with the older ATtiny841 (released in 2012), which was an upgrade of the original ATtiny84.