i know that around 70% of integration uses REST but i need some example scenarios where SOAP is preferred(not that REST can't be implemented)?
I am thinking of an example like, where we need to connect a legacy system and sync the bookings done in salesforce system with the legacy system for every 10 mins. is that right?
The only time you should prefer the use of SOAP over REST is when REST is incapable of handling the integration, or the third-party system does not support REST.
In your example scenario, you can use SObject Get Updated and Retrieve Multiple Records with Fewer Round-Trips more efficiently than getUpdated*( and retrieve().
At this point, there are very few, if any, SOAP calls that you can't do in REST, so the primary concern for most cases is whether your environment supports REST or SOAP better.
REST has many benefits, primarily reduced bandwidth and memory usage (in typical environments), and ease of use in supported languages. The only benefit that SOAP had over REST is that IDEs could auto-complete code without the help of a library, but since REST is so easy to use in most environments, that's hardly any benefit at all.
There was a slide from the API talk at TrailheaDX 2020 by Kris Harrison.
Do More With Less Code Using Salesforce APIs
The Enterprise SOAP API can give you strongly-typed enterprise entities. Essentially a snapshot definition of the sObjects that are exposed to the user generating the WSDL. How useful that is will depend on the language you are integrating from and how frequently the definition of the sObjects changes.
