In today's culture, you should be a billionaire now.
But more seriously, "agile", what does it even mean? I almost posted this on another comment.
There is no, singular, agile beyond the manifesto. Everything else is a variation either attempting to push the goals and ideas of the manifesto or attempting to capitalize on fads.
Scrum is borderline fad (I'm ok on the concept, but I think employees should be paid not to go to most Scrum classes; most implementations are incredibly badly done like they deliberately misread the guide). SAFe is bullshit (the gov't bought into it though, how's that F-35 coming along again?).
XP had (has?) some seriously dogmatic advocates, but most people have learned it's a toolkit and not a thing to do without consideration.
Lean has always been presented as a philosophy and toolkit, at least as far as everything I've ever been able to find on it. I think there are some moronic certifications out there, skip them.
DevOps is Theory of Constraints for IT. Which is not a set of ceremonies to perform, but a way of viewing and trying to improve the system. Though, like with Lean, many people are apparently illiterate and fuck it up.
So the question becomes: what version of "agile" were you using? And did you do one of the most important thing that, as I noted in another comment, seems to be the most crucial common element of most of these (except SAFe, fuck SAFe): Did you actively set about to improve the way you worked as you worked? Did you frequently ask questions like: Is this working for us? Is this working for our customers? Is this the right process? Are these the right tools? Are we holding it right or should we try something different?
If introspection and reflection and periodic adjustments to not just the product but also the team (structure and dynamics) and processes aren't in play, then it's probably a ritualized version of agile which is only barely better than Waterfall.