Could be a number of things. I find forums in general may be on the decline. A few hobbies I am involved in I would rather post on the Discord then on the forums, then throw in social media platforms and forums seem to fall way behind.
Everyone is different and I find I am content with my path and don't feel an overt need to discuss religion or spirituality lately. Like zoness said above, i have been here for over 15 years (different account now) and credit this place with helping me better understanding Christianity, then eventually leading me away from it. For a time, as I was a pretty solitary practitioner of whatever path I was on, CF was my go to for discussing religion and spirituality for many years. While active on CF I was a Christian, druid, Noahide, Muslim, anglo-saxon pagan and for a good amount of time a Buddhist of various practices and then eventually to becoming agnostic.
The real sign for me that CF doesn't hold much weight for me anymore as I now venture into the Catholic Church and I have no interest to even visit the Catholic forum here. I just pop into this sub forum, see nothing of interest and move on. Maybe posting here or there.
Anyways an interesting topic mr awitch!