Using a personal Mac or PC is fine in a startup - there are no strict rules at all.
But if it's a big company, they would love to spy on everyone by any means - like installing root ca for mitm, blocking all plugins for chrome, even using AI to identify user activities... a way of making trade-offs is the policy called BYOD - usually IT team will set up the whole remote working infrastructure, and we can install a remote desktop client in our personal computer to connect into the company network.