That's the thing with all these UE games: Deluded, Beasts in the Sun, Modern Luxury, Silicon Lust, Bioasshazard, Delta Zone and many others.
Games starts really strong, and there's a lot of promises for the new content. But eventually updates become less frequent and each update includes less content than the last.
Not to speak of some developers who just LOVE to switch from UE4 to UE5 bringing a lot of new bugs in and lowering FPS in half

.
I guess it's patreon model which incentivizes devs to milk their customer as long as they could.
BTW I am not even complaining, just temper your expectations and play other games inbetween releases.