Even that much is only one of her main powers. She's a lot more overpowered than that.
(It helps a lot in Touhou/Gensokyo, where just about everyone is S-class or higher by Worm standards. Wriggle Nightbug, who basically has Skitter's power, is one of the weakest characters...
To put it mildly.
Literally the ONLY two reasons that Yukari doesn't go GodModeSue in canon, is 1. It tires her out something fierce to even do what she currently does, to the point she'll sleep 12+ hours a day, and...
2. Its boring as hell for her.
And its mostly #2 as the reason, considering there have been times where she has been active for days/weeks straight (pre-Hakurei Lunar Incident) with little rest, likely via using her boundary manipulation to alter the line between tired/sleepy and energetic/awake on herself. Never confirmed though.
Its the onset of ennui that is the driving reason why Yukari acts out the Mastermind plot role in Gensokyo.
If she really,
really, wanted someone
beyond dead, they'd be dead. And even Reimu wouldn't be able to stop her. To be blunt on this: Yukari's powers work
perfectly fine, in the Netherworld, in Heaven, and beyond the Sanzu River. She is that utterly broken power wise.
And there are tons and TONS of Youkai or other non-humans in Gensokyo that would be considering just one step below her. Tons.
Even the low end 'mooks' are terrifyingly powerful. Cirno took on Utsuho, at the core of Old Hell's reactor....and won. A being that controls, shapes, and can ex nihilio create fusion reactions in the form of micro-stars, ad infinitum, was beat down by an 'ice' fairy. Although,
depending on your calcs, said 'ice' fairy might actually be able to locally manipulate entropy itself into manifesting as drastic temperature drops down to, potentially, absolute zero.
I mentioned Sakuya a few pages back, and, for all she is my favorite character, she's low to mid tier at best.
A time-stopper, tesseract creation/manipulation flying assassin....
Is LOW to MID tier only.
There are extremely good reasons why some view Gensokyo as a self-contained deathworld right on par with 40k's Cadia....if not worse. (Case in point: Never fuck with Yuuka Kazami's sunflowers.
EVER)