Own the difference. Rent the rest.
Most teams don't need their own models. The advantage is usually in your data, your workflow and your user experience.
Buy a tool
Off-The-Shelf
“Is a generic tool good enough?”
Gain: speed
Cost: generic, little control
Build on APIs
Models + Your Product
“Can our data and UX make it better?”
Gain: fit and control
Cost: evals and upkeep
Train your own
Fine-Tune Or Train
“Is there no other way?”
Gain: specialisation
Cost: data, skills, time, money
Prove value before you build the engine.