SOAP (Simple Object Access Protocol) is a standards-based web services access protocol that has been ruling the integration world for a long time. SOAP-based web services were the de facto standard for SOA (Service Oriented Architecture). As the architecture moved from SOA to Microservices the enterprise started embracing the new philosophy from Roy Fielding, which we call today REST (Representational State Transfer). REST is an architectural style that relies on HTTP protocol without any support of higher level protocol like SOAP.
Below are major reasons for the popularity and motivation for moving from SOAP to REST: