Will my face return to its original state immediately once the filler effect wears off?

I've become interested in fillers and have been looking up various things, and I find there are actually more questions than I expected haha. Among them, what I want to know most is what happens after the duration of the effect wears off.

I heard that fillers are naturally absorbed over time, but I'm not sure if the effects disappear suddenly or if I gradually return to my original appearance. As someone receiving this for the first time, I think this aspect is quite important.

I am also wondering if it might look worse than before the procedure just because the maintenance period has ended. Some posts online say it simply returns to its original state, while others say it varies from person to person, so I would like to hear the opinions of those who have experienced this.

I am also curious about the intervals at which those who regularly get fillers undergo re-treatments. I would like to know if you get them again when the effects have almost completely worn off, or if you get them for maintenance while there is still some left.

If anyone has been getting fillers for a long time, please share your satisfaction level as well. I would be really grateful for any advice that might be helpful for someone just starting out. I'll be waiting for your reviews^^