I don’t think this core paradox applies to all players. I know I don’t need to be seriously “immersed” as a character to really get hit by some important choice they make or action they take.

As a side ways analogy: The Sept of Balor was a big event, and I watched it with friends. I had some who were shocked, some who hid their faces, and others who laughed. I don’t think those that laughed are somehow less invested in the thing.

Put another way, I’m not sure “taking it seriously” is a sign of true investment. I think participation is the only signal we have for investment.