That's one possible route, though may not be the ideal "esports way" since you get the low-Hz lag effect, though that can be the lesser of evil in many situations.
Now, what you did may be the lesser of evils, with zero contention and excellent keyboard mechanicals (if mechanical). Now, a good old mechanical keyboard, does have keyboardfeel advantages for some. That may outweigh.
Just FYI -- even in Amazon Europe, the PCIe USB cards are cheaper than that.
There's multiple problems to fight simultaneously:
- Latency from having too low keyboard Hz
- Latency from USB contention (interference between USB devices)
- Latency from keyboard mechanicals

