I think the other reason, besides micotransactions being more profitable, is it's just a better business model for most companies. Having a reasonably predictable regular income is preferable to a one off hit or miss of a single player AAA game.

Companies like Sony still do it, but Sony gets a cut of every transaction on their platform, so they have their regular income as well.

Microsoft has sort of figured out a solution with gamepass where they can make large offers to devs in order to minimise their risk.

Whole industry is shifting towards it.