It's quite naive to assume that. There is a reason why it is deprecated by Apple.
Apple is likely preparing to remove it for a secure alternative and all it takes is someone to find a single or a bunch of multiple vulnerabilities in sandbox-exec to give a wake up call to everyone why were they using it in the first place.
I predict that there is a CVE lurking in sandbox-exec waiting to be discovered.
On the other hand, the underlying functionality for sandboxing is used heavily throughout the OS, both for App Sandboxes and for Apple’s own system processes. My guess is sandbox-exec is deprecated more because it never was adequately documented rather than because it’s flawed in some way.
As I understand it, Chrome, Claude Code, and OpenAI Codex all use sandbox-exec. I’m not sure Apple could remove it even if they were sufficiently motivated to.
Is there a better alternative on Mac?