the monero supply is also fixed and predictable, theres no difference except you trust Bitcoins supply issuance to stop sometime after you're dead.
also if you think supply inflation prevents something from being hard money, youll have to explain why gold has been a solid SoV for 4000yrs.
moneros annual supply inflation is ½-⅓ golds.
the problem with a hard cap isn't that there aren't enough monetary units. the problem is that you incentivize SoV as much as possible and disincentivize MoE as much as possible. everyone defers spending when their money appreciates in buying power (without them doing anything.)
meanwhile people who actually USE Bitcoin for purchases pay the network security fees.
this is an extremely bad incentive structure.