I would not necessarily agree that your reason makes Bitcoin better than fiat money, I think this makes Bitcoin different or unique. Whether this is better than fiat is more of an ideological or economic theory type of question, but being unique may be sufficient to ensure Bitcoin can have significant value.

For Bitcoin to be more unique or interesting, it must be resilient against not just a small privileged group taking control, but even a majority being able to change the rules and create new inflation. Luckily I think this is the case, even if Bitcoin grows and a large wave of users enter the system and there is a successful coordinated propaganda campaign which convinces the majority of users and miners to create new inflation, the system may still be resilient enough to prevent this rule change.

You maybe think about hardfork right now, but a hardfork requires more than just majority consent, it requires no significant opposition to succeed. This is because any significant opposition is able to cause disruption and uncertainty around the period of a hardfork, which will be unwelcome and troubling to businesses and users in the ecosystem, who value uptime and reliability. Businesses and users are therefore incentivized to oppose contentious hardforks.