Well yeah, you can apply that to most problems you encounter as a company - there are service providers for pretty much anything you can imagine. That doesn't mean it's smart to spend a huge chunk of your revenue on OpEx, however.
Sure, and you need to do the build vs buy math, but why not take the "If you can’t handle that comfortably in an afternoon, you probably shouldn’t be entrusted with customer data." logic further and say
1. Don't use a third-party auth provider, if you can't build out an OAuth provider in an afternoon you shouldn't be entrusted with login credentials
2. Don't use Github, if you can't build out an internal Gitlab instance in an afternoon you shouldn't be entrusted with securing source code
3. Don't use Github Actions or CircleCI, if you can't self-host a Jenkins server in an afternoon you shouldn't be entrusted with secure deployments
4. Don't use a lawyer or outsourced HR, if you can't draft legally binding employment agreement in an afternoon you shouldn't be entrusted with hiring people
That's a straw man, obviously: I didn't talk about building your own database, but setting up PostgreSQL and pgBackRest, two well-defined, and thoroughly documented applications. With coding agents available, you don't need to much arcane domain knowledge for the fringe details, so a lot of the old reasons for appliances as a service don't hold anymore.
Other than that, yes! Setting up a Keycloak instance as opposed to handing over login credentials to Octa should be a consideration. Keeping your source code in GitLab over tying your entire development workflow to Microsoft vibe coders with an awful track record is a sensible stance.
> Don't use a lawyer or outsourced HR, if you can't draft legally binding employment agreement in an afternoon you shouldn't be entrusted with hiring people
That's a little ridiculous; there's an overlap between someone setting up a database for a startup and someone programmatically using a database at a startup. The overlap between that person and someone with a legal background is infinitesimally smaller.
1. Don't use a third-party auth provider, if you can't build out an OAuth provider in an afternoon you shouldn't be entrusted with login credentials
2. Don't use Github, if you can't build out an internal Gitlab instance in an afternoon you shouldn't be entrusted with securing source code
3. Don't use Github Actions or CircleCI, if you can't self-host a Jenkins server in an afternoon you shouldn't be entrusted with secure deployments
4. Don't use a lawyer or outsourced HR, if you can't draft legally binding employment agreement in an afternoon you shouldn't be entrusted with hiring people