However, there are always reports here in the thread that the code doesn't arrive, so it might be a problem from time to time.
This is what makes this whole thing so bizarre. Why in the world did they opt for such a crappy system in the first place and why do they insist on sticking to it despite all of these constant complaints?
To be honest, I have never had any problems with the system myself and I am familiar with similar systems from other platforms such as exchanges.
But you could certainly switch to a classic 2-factor with a 2-factor app like the one from Microsoft, which is also quite common on exchanges or other gambling platforms. However, this also means more support effort, as there will always be cases where 2-factor authentication is lost (cell phone theft without security, etc.) and you will then have to switch to much more complex procedures, e.g. with passport checks or similar.