As a startup, the last thing to worry is vendor lock-in. With an architecture like this, you got fast time to market, minimal operations, scalability, zero starting cost, fair pricing. Just my 2c.
actually it's not the last thing to worry about. I deliberately didn't vendor lock-in with my startup, and now I can deploy to Azure, AWS, and anyone who has a linux box. Being vendor independent has opened the door to a lot of sales that would not have been possible otherwise