I’m not sure having an axis and being in the top right of a competitor landscape slide is necessarily wrong; surely what matters is what is written on those axis and which other companies the startups display?
Any plot on two axis should be a macro positioning slide — the equivalent of top down if you like, which should demonstrate where the startup desires to be and the primary way in which they differ to other companies or startups in the same space who compete for the same customer.
The other slides you suggest most definitely communicate more detail; zooming in on the specifics for each business and the way a startup will address each element of the proposition. For sure this provides more depth of understanding, but without the ‘macro’ landscape axis slide, unless an investor is intimately knowledgeable about that specific market, jumping in straight away with a very detail heavy slide will force the reader to work much harder to understand the context.
Investors receive too many decks, skim through them too quickly and are extremely short on time and patience. It’s vital to set a scene to maximise communicability.
Simple slides are not bad, like anything else, it’s what’s actually written on them which is important.