After the 2019 revision of the SI, this definition [of the metre] was rephrased to include the definition of a second in terms of the caesium frequency ΔνCs.

https://en.wikipedia.org/wiki/Metre

If you want to be even more pedantic you could say no metre stick is exactly 1 metre long according to the current definition of a metre. If you want to be scientific then all of them are within some reasonable range like 1.000 ± 0.002 m. If you want to be historic then at one time there was a perfect metre stick

In 1799, the metre was redefined in terms of a prototype metre bar. The bar used was changed in 1889, and in 1960 the metre was redefined in terms of a certain number of wavelengths of a certain emission line of krypton-86. The current definition was adopted in 1983 and modified slightly in 2002 to clarify that the metre is a measure of proper length. From 1983 until 2019, the metre was formally defined as the length of the path travelled by light in vacuum in 1/299792458⁠ of a second.