Can I remind all that the thread title included the words which individually are fine...
Marmite does not fulfil that definition
It's just salty meh. Or as a friend of mine once loudly announced: 'it tastes like cum' before realising what she'd just said to a tableful of people she barely knew.
To be fair, I don't think Marmite is meant to be eaten
individually - unlike peanut butter, which is at its best consumed straight from the jar with a spoon. The saltiness is the very raison d'etre of Marmite - it's more of a seasoning than a main ingredient, akin to Worcestershire sauce. Poached eggs on toast, for example, are immeasurably improved by a thin smear of Marmite on the toast, but layer it on too thick and you render the whole dish inedible.
Cum may well taste the same as Marmite but it has a very different consistency and would just make the toast soggy. Which might be acceptable in British public schools but not on my breakfast table, thank you.