That post is flawed. First off the comment below it explains that the passive can't just be ignored. At a 32% damage vs 12% damage, even the (bad) formulas will swing in favor of Lost Prayer.

But let's get back to that later. Ffirst let's address the bias comparison. If attack is king like you said, what happens if instead of taking 62.2% crit damage, we take 46.6% more ATK%? Well, actually the comparison gets a lot closer. The stats OP and the commenter both went with are actually the wrong stats to pick (at least for this formula).

Skyward Atlas(with 90 crit damage, 33.1% ATK): 807.3846 + 897.094 = ‭1,704.4786‬
Lost Prayer(with 90 crit damage, 46.6% ATK): ‭802.1952 + 891.328 =‬ 1693.5232

Way closer, right? So now that we're not intentionally gimping the comparison with bad artifact picks, let's go back to that other comment about stacks. Now obviously at 0 stacks, Atlas wins. And at 4 stacks, Lost Prayer wins. What about at an average of 2 stacks?

Skyward Atlas: 1,704.48‬  * 1.12 = 1909
Lost Prayer: ‭1693.52 * 1.16 = 1964

Suddenly Lost Prayer is king again.