I agree with that, with the qualification that  'Bitcoin as a medium of exchange had two limiting ...'. This is as opposed to 'Bitcoin as a store of value', which is a more successful story.

Having more people with some sats on their phone increases the need to do something more useful with those sats, so zapping new people can move the needle just a tiny bit -- very tiny bit.

I expect more significant merchant adoption will happen only (where/when) the merchants are themselves incentivized to accept (and keep!) sats; the desire of the buyers projected onto the merchants is a much weaker force.