Note I was writing this as I read, and only read the end... well at the end. LOL. I am posting because it holds valid for someone who accepts the previous arguments you were making. Peace.

Note that I am not claiming there is no such thing as "Objective Truth"; I am stating that there is no way for us to grasp it.

That's the fallacy of thinking we need an absolute total understanding of everything in order for objective truth to be understandable as certain aspects, attributes, properties and characteristics of the diversity, variability and multiplicity of existence.

Subjective truth in relation to objective truth, means a personal determination that can be made without existence to verify the proposition. We can believe whatever we want as "subjective truth", but it doesn't make it so in objective reality.

The video you show demonstrates what I'm talking about, how subjective determinations devoid of verification and actual grounding in reality, can often be false. Ideas and beliefs are great to explore, but truth is a synonym for reality and requires reality to validate it.

Secondary sources that validate a certain thing can be more relied upon if they verify the same things in reality as being such. We can't, or shouldn't, be redoing re-verification of every single thing ourselves such as experiments scientists can conduct which we are limited from doing ourselves. What they say is true so long as it is true, based on our belief, trust, faith and loyalty in what they say. We can be fooled by them, and we can fool ourselves as they can fool themselves and then fool us in consequence.

This is part of biases, sensory limitations, etc. but there is still the objective reality that is shared in common for common knowledge to be attained and communicated about. The fact that we can't be in the same space at the same time in the universe certainty doesn't preclude the ability to discern objective truth from reality.

As you say, the subjective truth we each want to reference through different means, such as rulers with different measurements, is a problem we created, not reality.