There is no such “standard of care” in this medicine field regarding which cases should go with the procedure of ICSI and which should not.
In most of the clinics this process is used for severe male factor infertility, and many use it on every case. The large majority of IVF clinics are somewhere stuck in the middle of these 2 intense processes.
Our thinking about ICSI has changed over time, and we are now doing more ICSI than we were doing it years ago. As we learn more about methods to help couples conceive, our thinking will continue to evolve.