I was focusing mostly on your incorrect claim about account ages. The reliability of the information (speculation vs. solid info) is another can of worms.

The reason why you see mostly speculation is because nobody knows how the algo work, except people inside Reddit itself. The most that people can do is to analyse patterns, and come up with a hypothesis explaining it; and while doing so by subjective means is by no means optimal, it is better than nothing.

Where’s your critical thinking ?

Critical thinking is to neither change the goalposts once people contradict your claim, nor to conflate hypotheses with gullibleness-based argumentation (“I swear it’s true bro”).