You raise an interesting question here, Tim. I became a FOM because I thought it may help other writers who I read, and ultimately may attract reads from other FOM.
This may well be the case, but I have not noticed any increase in my own earnings. I was actually earning more on average per month in 2023 before I became a Friend of Medium , even though I have I increased my output and engagement.
That said, in 2023 I was receiving one boosted article about every second month, since then ( and becoming a FOM) I haven’t had any boosts, so that does have a significant effect. Income had been steady nevertheless in recent months, until a slight drop in December. It will be interesting to see what 2025 holds.