Token EPC guy here. I honestly don't know what to make of the numbers, by the grace of God the EPC churches in La. are doing reasonably well.
@Pilgrim might know more than I do on this point.
I've never been a member of the EPC, although I've attended or visited several congregations. I have heard that some in the EPC are very "woke" but I don't know that a reaction against that would account for all or even most of the losses. But I'd be surprised if it isn't a factor. Plus, how many Revoice fans and proponents of "Side B" Gay Christianity are there in the EPC? That's another big controversy that would lead to defections. And some may leave churches if they think it is too conservative on those issues.
Other factors:
Given the typical demographic of the average mainline (and even Reformed) congregation, some of the losses are due to death, I'm sure.
As at least one other person noted, some of the losses may be due to people who opposed the move to the EPC (or were ambivalent toward it) and perhaps a subsequent "rightward" turn in the ministry of the local congregation and eventually left.
Maybe some people got turned on to Reformed theology if that became more of an emphasis and decided to go more thoroughly Reformed.
I do think that the EPC has to be said to be functionally egal even if a congregation doesn't even have women deacons, much less elders. (And those definitely exist, although I have no idea what the percentage would be.) Since there are women elders in every Presbytery, isn't there a sense that every member is submitted to women elders? At least in terms of numbers, this has been a big change with the PCUSA congregations coming in. Before that, the idea that many egals had was that the EPC was generally hostile to egal regardless of their "open" stance. 15-20 years ago I think there was literally a handful of women Teaching Elders.
The Presbyteries that Jacob and I are familiar with are among the most conservative in the whole denomination, so what we're familiar with isn't tremendously different than the average PCA congregation in some respects. What goes on elsewhere may be much further to the "left." If the PCA is much more "liberal" outside of the South wouldn't it be safe to assume that that's more or less the case with the EPC also? What are EPC congregations like in the Northeast and West Coast?
The nature of something like the EPC is that it will be too liberal for some and too conservative for others.
I don't know how much it has really grown, but the ACNA seems to be getting a lot of press these days. There seems to have been an influx of former Baptists and others who are drifting leftward on women's ordination and even sexuality, which is alarming considering why the ACNA was formed to begin with. My theory for a long time has been that some of the Kellerite people would probably be as comfortable in Anglicanism and maybe moreso, but practically speaking it was not really an option in many places.