Matrix Organizations

I'm curious to know how to decide on whether a matrix organization is appropriate or whether a restructure should happen to align the manager with the project lead.

Based on the table below as a simplification of my organization, at what point would you go to "Future State", having once been a non-matrix organization (Previous State) and nox being a semi-matrix one (Current State)? And a closely related, at what point would you say the semi-matrix is the right one? Some things that jump to my mind are:

• alignment is better than matrix where possible
• people's careers need continuity and changing managers breaks that continuity
• some matrix organizations are necessary, like when they're is a team that sits outside of projects and comes in only when a team needs their skillset for a task or period of time (in the podcast, architects are the stated example)