The phrase "always inadequate" is correct and usable in written English.
It can be used to describe something that consistently fails to meet expectations or standards.
Example: "Despite numerous attempts to improve the system, the results remain always inadequate for our needs."
Alternatives: "perpetually insufficient" or "consistently lacking".
Thus, the single-grab sample is nearly always inadequate.
Climate is not just the "average weather" (an obsolete, and always inadequate, definition).
Provision for pregnant, elderly or disabled people was "almost always inadequate".
The telephone system, always inadequate, suffered a severe blow when a major earthquake in 1985 destroyed the city's main exchange; in the late 1980s a decentralized system was installed.
Buffy Paradigm: "What expertise there is consists largely of bad or uncertain advice and old, flawed and confusing technical data.... Arcane knowledge is always inadequate and fails to predict, detect and properly characterize the threat".
Until then, reach the age of 75, as I did just before the law changed, and you had no choice but to buy an annuity for the best (and always inadequate) price on offer.
Auditing will always be inadequate and can never make up for the choice of a bad business partner.
My comprehension of his tons of shaped steel always feels inadequate to their conceptual subtlety, engineering sophistication, and, oh my, size.
Yet this explanation has always seemed inadequate, with the government privately admitting to having sometimes shelled the "no-fire zone", an area of the battlefield it declared as a sanctuary for entrapped refugees, of whom perhaps 50,000 remain.
However, in a solid form these alloys have always exhibited inadequate fixative properties in the surrounding bone.
The parody sold by Urban Outfitters and Hipster Ariel memes always felt inadequate.
