agile "agile" is an oxymoron
That's why agile is a bit vague and waffly as well. Because world+dog now calls themselves agile. And then you get all these pedantic types telling others they are doing it wrong, aren't pure enough, etc. They are the priests of agile. And they get hired by big companies for lots of money to help them become agile. Of course that requires some compromise and they adapt their definitions and standards until it's all agile and wonderful. Because the alternative would be admitting failure, which isn't mutually beneficial. You are kind of doing waterfall in an agile way For example, you plan 20 scrum sprints ahead and then act surprised reality has different plans. It's still as dumb as waterfall ever was.
Most of these companies of course deliver software just fine. They don't do it particularly fast. Or well. Also they aren't that flexible. Or particularly quick to adapt to changing circumstances. I.e. all of the things one would associate with being agile (in the adjective sense). But it's good enough to call themselves agile and still feel good about it.
People were doing awesome software long before agile development became a thing. That was never conditional on being agile (whatever that means). I've been around long enough to have seen the before and after the post-it shufflers came in and made our walls all colorful. And I can tell you that the average software project is just about the same level of a disgraceful mess as it was thirty years ago. We do a bit more of it and a bit differently. And we got some nice tools that remove some bottlenecks from our process (like automated tests and CI) and make us more productive That's not agile, it's using better tools and it helps. The tools definitely improved massively in thirty years.