I tried to introduce the ICS concepts formally and up-front, but met a lot of pushback; "we don't need that", "we're not dealing with fires" or "it's too complicated".
By using ICS principles without calling them such, people usually see the value. I even got a sizable promotion and raise due to my "clear and concise handling of several serious incidents and putting procedures in place to handle similar in the future". All I did was direct people in to ICS functions and act as an IC.
I agree that ICS concepts should use used more widely and outside of just emergency services, but getting past the "stigma" of the title is the hard part.
Really useful training, have had to use it multiple times to coordinate responses ransomware, and other IT disasters, and does benefit from the buy in of senior leadership at the company I work for.
Biggest challenge we have is keeping ICs after deciding to centralise the IC organisation in 3 locations, all ICs were offered the choice to relocate or leave.
We have a lot of very new ICs.