Meng was PRC royalty - the daughter of Huawei's president, imagine a literal billionaire being a spy. She was taken hostage under Pence's China Initative for Iranian sanctions shenanigans that historically was dealt via fines. The initiative explicitly called for targetting PRC nationals.
Hence intense reaction. The 2 Canadian Michaels on the other hand, were text book spys with NGO covers. Western propaganda likes insinuate PRC would capture innocent westerners when state security have massive state survillance capability that completely dismantled CIA networks a few years prior. Like literally friend of Michael hinted he was in "intelligence" and CSIS (Canadian CIA) publically celebrated on twitter upon their return. The Michaels weren't executives. The TLDR, while in PRC, don't traffic drugs, don't be a spy/do anti state activities, don't get involved in expensive legal proceedings - the latter is what actually get (white) westerners in trouble via exit bans.