I see people saying that X and YouTube are now very difficult to do, with high initial investments but almost zero income, and that overseas Chinese-language users are relatively few, making it more difficult to run a Chinese account compared to an English one.

I strongly agree with this point.
But I don't think overseas self-media is completely not worth doing.
The real value that overseas platforms bring is the possibility of earning income abroad. What you hold is a currency that can circulate freely overseas and be freely invested.
This money does not occupy foreign exchange quotas, and you can freely use this portion of funds to invest in Hong Kong, US stocks, and other overseas assets, effectively providing many more ways to make money grow.
I believe that even just for this reason, it's worth spending time to accumulate and to take a chance.