True, we don't know what her growing conditions are.
However, waiting four or five years before repotting would be a death sentence for many phals. She needs to repot them periodically.
How quickly the media degrades depends on what is used and on the growing conditions. For example, my media degrades faster in the greenhouse than it did when I was growing in my home.
In general, usually they should be repotted every other year.
Janice, I recommend taking one of your wilted-leaf phals out of its pot. What does the potting media look like? What do the roots look like? If the potting media looks more like soil than separate chunks, it's well past time to repot. If the roots are soft, squishy and brown, they are dead. Cut off any dead roots.
Repot the plant in fresh media. Make sure the pot fits the plant. If you had to cut off many roots, you will need to get a smaller pot.
When you finish potting, jot the potting date and plant/root condition on the back of the plant tag to keep track of when it was last repotted.
As for what to use for potting media, that can be a huge debate. In reality, it depends on what you are growing, your growing conditions, and your watering habits. I use a mix of bark, perlite, charcoal and coconut husk chunks. Others have success with sphagnum moss or semi-hydro extruded clay pellets. If your plants did well initially when you repotted them after they were purchased, you might want to use that again, as it seemed to work for you until it degraded.
Mounting plants is great, but not practical unless you have a sealed growing environment (grow room or greenhouse) that has a high humidity. You must also water much more often. I mount many of my plants, but I grow in a greenhouse. When I had the grow room in my home, it was more difficult to maintain a high enough humidity to make the mounted plants happy.