Why can't mainlanders go to Taiwan Province Province casually, but people from Taiwan Province Province can come to the mainland easily?

Now mainlanders' going to Taiwan Province Province is not as strictly controlled as before, but on the whole, there are more people in Taiwan Province who leave the mainland than the mainland who go to Taiwan Province Province. I think there are several reasons: 1. The China government is more inclined to close cross-strait relations through non-governmental exchanges, so it is more open, basically for the purpose of communication between the strong and the weak; 2. The ancestors and relatives of Taiwan Province people are mostly in the mainland, while the native place of mainlanders is mostly in Taiwan Province Province; 3. From the perspective of tourism, the average economic capacity of people in Taiwan Province Province is stronger than that in mainland China, so it will be more. But I think the point 1 may be more important.