Do you know any person who can go back to waterfall after 2 years of scrum? I don't. BTW, I personally know hundreds of people moving to agile after years of experience in waterfall. Why is that?
"Think and act" to learn to "inspect and adapt". Isn't "adaption" one of the best quality of humans? Why do you need to fall in a trap of non-adaptive processes?
Be honest to yourself and to your team before giving excuses for not using agile.