For me, best of times was definitely roughly 2011-2015, before Amazon became a publisher (rather than just a distributor), back when small publishers were still able to operate. My career was on an upward trajectory. Every one of my releases hit the bestseller chart for my genre, without fail. I wasn't making tons of money, but it was more than I'd made working my full-time office job, which was good enough for me. Overall, everything was going my way.
Well, you know what I'm going to say about "worst of times" now, don't you?
The minute Amazon became a publisher and began driving small presses out of business, my entire career took a nose-dive. I wrote about this in depth a few months ago, but the TLDR is that I don't write fast enough to stay visible in Amazon's current algorithms, which favor quantity over quality. (I'm not saying everybody who writes fast also writes poorly, but authors who churn out 12-20 books per year have to be cutting corners somewhere. I think there are very few people who can write that fast and still produce a polished, well-developed story.) I'm now making approximately 1/3 of what I was making in 2015, even though I have twice as many books out now. And if I'm being honest, it can be hard to keep the faith and keep writing. I honestly just keep hoping there'll be another big shake-up in the publishing world that will flip the tables again. Until then...
I don't know. The more I think about it, the less I want to write, and so I do my best every day to NOT think about it.
So now that I've been a total downer...