I’ve worked with a few people from NCC Group, Matasano, security staff at Airbnb and OpenAI, all carry and recommend iPhones for security footing. Depending on threat model, “lockdown mode” on iOS has a lot of what is useful in Grapheme like turning off built in connectivity services & disabling JIT and other code paths in the webview.

To each their own, I certainly would not recommend an iPhone in this scenario, especially even more at a top tech company.