The person you're replying to did not say that, you're arguing against a straw man. Looking at the manual, upgrading to 18 seems straightforward, matching the "minimal efforts" they mentioned: https://react.dev/blog/2022/03/08/react-18-upgrade-guide
Arguing isn't the correct word for that. I did express incredulity when asking for clarification.
The person I was replying to did minimize the effort involved in upgrades by enclosing it in parentheses.
The incredulity is based on experience. Sure you can follow the upgrade guide, and if you work at Meta there are many people that know about weird edge cases. If you don't work at Meta, then you may be spending time chasing down bugs in production on your own. That gets expensive.
