This means that teams must make an up-front architectural decision to develop apps in a server-agnostic manner, and developers must stay disciplined to keep components portable from day one, but you can get a lot of mileage out of free credits without burning dollars on any infrastructure. The biggest challenge becomes finding the time to perform these migrations among other competing priorities, such as new feature development, especially if you're growing fast.
Our startup is mostly built on Google Cloud, but I don't think our sales rep is very happy with how little we spend or that we're unwilling to "commit" to spending. The ability to move off of the cloud, or even just to another cloud, provides a lot of leverage in the negotiating seat.
Cloud vendors can also lead to an easier risk/SLA conversation for downstream customers. Depending on your business, enterprise users like to see SLAs and data privacy laws respected around the globe, and cloud providers make it easy to say "not my problem" if things are structured correctly.