The pretty minimal RV32EC core Ibex is estimated 15k gates: https://github.com/lowRISC/ibex
But, the similarly minimal Arm Cortex M0 is, drumroll, 12k gates.
Not saying this means Arm is better than RISC-V, such a small difference can probably be explained by some microarchitectural feature or lack of it. Just that you can scale down Arm as well.
But yes, I can see tiny chips like these putting a squeeze on 8 and 16 bit microcontrollers.
It might also be successful, even in that segment. The RISC-V ISA was specifically designed to scale up (e.g. to OOO and vector processors) while still being very simple, especially at the low-end - a basic RV32E is really comparable in complexity with many real-world 8- and 16-bit chips.