Yes, even in other countries who provide 19Gbps to household However, if you have many interconnecting devices in house that are transferring data to each other, then it is still beneficial.

If you have extra money to spend on it, you can still upgrade. There is still benefit to it. The higher the capacity, the more challenging to design the circuit board because the board has to have lower noise to handle much more complex modulation for example. By doing so, the quality of signal received at lower speed is also improved. I can bet that link speed would also improved compare to your previous router.

Me, I just wait until price drop when new one enter market