This is not remotely accurate. Plenty of large tech companies still play in China. The difficulties are very high but if you are big enough the huge market size it’s still very profitable. I don’t think google/etc are in China for its slave labor.
Depending on the segment you are in within the tech industry, the Chinese subsidiary of the foreign company might be a white-labelled Chinese offering (eg. AWS China, Azure China) or entirely unique IP developed in-house by the Chinese subsidiary.
The affiliation with Chinese companies is borderline fine print, white labeling would be if you had "tencent cloud" which happened to behave exactly like Azure.