The trend for using blackbox connectors to access Rest APIs means you are sending and receiving data in a pre-determined way, they often don’t offer all the functionality of the system you are connecting to, so there is little or no customisation/control for your application. For example, if you use Zapier or Make to connect your no-code app to another SaaS eg. Stripe to take payments from your customers, it will take your customer data in a prescribed way and return the data in a certain pre-formatted way. Using them limits your options to do anything different to your competitor who is using the same APIs. As a general rule, every time you use a blackbox connector you are reducing an element of control over your programming, so the more you use, the more this effect starts to compound and at a certain scale of interconnected processes this starts to seriously limit your options.