How do you feel about ZUN's handling of Touhou's power creep? Newer characters like Hecatia, Okina, and Yuuma are much bigger deals than Yukari or Kanako. Even a Watatsuki sister is a stage 5 boss now.
That's not how it works / I don't caaare.
That's not how it works: Toyohime is a stage 5 boss because that's her spot to appear in the plot, not to indicate that she's halfway between Yuiman and Ariya on some power level ladder. Just like Yuyuko wasn't demoted to weaker than Kyouko, Yuugi vs. Nitori is probably not an even match, and Reimu & Marisa probably aren't between Keine and Reisen. While I wouldn't deny that stage placement, especially in the later stages, seems to broadly correlate with some sort of power level, it doesn't work as actual evidence of relative power (either within or between games) when there's any other points to consider.
I don't caaare: Any supposed power creep hasn't had a practical effect on either my opinions of characters, the events occurring within Touhou stories or the identity of the series as a whole. It would be one thing if Touhou, say, originally had an identity of starring especially weak characters and then escalated from there, or conversely if specific characters being the top dogs had been really central to the series somehow. But neither of those is true, and even when the status quo within Gensokyo has changed, it's never because someone more powerful than Yukari (the usual power level hobby horse) showed up, it's because somebody likes meddling.
The likes of Kanako, Mamizou, Nitori, Aya, even Miko and Byakuren or freaking Chimata have done far more to steer Touhou stories because they like to cause problems within Gensokyo, and even Okina's points of relevance haven't been about her being particularly strong. Meanwhile, the likes of Hecatia, Keiki, the animals and Zanmu (so far) have had very little impact on things. They certainly would/should have an impact if they were in Gensokyo, but they aren't, and I do think ZUN also feels that gives him a bit of leeway in making them more powerful bigshots than if he had to fit them in the Gensokyo ecosystem.
I guess that's the closest I come to an answer on how I feel about ZUN's "handling of it": all the supposed power creep characters are pretty well insulated from actually being a problem. Or often relevant, which I find a shame.
But to begin with, power levels only matter when I think being strong makes a character cooler, and stage placement only matters when I want an excuse to think a character I like is strong.
On a side note, I have no idea why Okina is on that list. Or Kanako, on the other team. Least powerfeaty 2010s boss meets least powerfeaty 2000s boss.