
AddictedBLYaoi:
On the description page there's also voice actors. Do they use voice actors? Or the voice actors are for podcast version?
There are professional voice actors dubbing everyone except for Zi Yu, who did did the dubbing for himself.
Dubbing is par for the course in C-dramas, for a number of reasons. One is that it can be hard to eliminate all the surrounding noise, another is that actors may not have a voice that fits with the character, or that they have a dialect or regional accent that doesn't fit the character (China is BIG and has a huge variation in dialects and even languages). Or that they are inexperienced as actors and might not be great at delivering their lines well.
Some actors have good voices and good line delivery and often dub themselves, so in those cases you are hearing their own voice, just not the way it was spoken during the filming.