The reason linear A is so difficult is that the total remaining corpus of Linear A text is ~7500 characters, spread out over ~1500 inscriptions.
If you have a 4k screen, you can fit all remaining Linear A text on your screen at once, in 14pt high font.
Very vaguely, it makes it like a one-time pad where it can be anything you want it to be. Not quite, but so little text leaves a lot of options open.
As observed by archaeologist John Younger, the entire Linear A corpus takes up only 1.84 pages of letter paper when typeset in 12 point font and 1-inch margins.
when I first read the title thought he was talking about linear algebra and I was like damn it's not that hard
An in addition to that, a vast majority of documents are lists which consist of a "header" (1 to 3 words) and word-number pairs afterwards. An another common class are small clay seals with 1, 2 characters carved into them. It's likely that in both cases, we may be dealing with abbreviations.
Some of the lists end with "ku-ro" and a number that's the sum of all the previous numbers, oddly frequently off by one.