The costs only have to include amortized training costs if you are trying to be profitable overall. Having positive unit economics and VC subsidized fixed costs is pretty standard.
What happens when the VCs decide to stop dumping more money onto the fire?
Positive unit economics means that inference as a business continues regardless. The VC's no longer dumping money in means no more training new models.
Not if there is competition who does train newer and better models.
By lighting VC (public soon) money on fire...
So then the entire industry stagnates and most of the companies go bankrupt because they are all selling hype about what models "will" do in the future, not what they do not, and what they do WELL now is very limited.
this would never work if the core business model requires your flagship product to be best-in-class.