Refresh Now in Power Bi service

i looked into Log analytics and captured the command sent to Analysis service to refresh the model 
it is a full refresh as per the following query (i removed only my database id)
also refer to this link to understand the parameters of refresh type

[MS-SSAS-T]: Refresh Model | Microsoft Learn

<Batch Transaction="true" xmlns="http://schemas.microsoft.com/analysisservices/2003/engine">
    <Refresh xmlns="http://schemas.microsoft.com/analysisservices/2014/engine">
        <DatabaseID>123</DatabaseID>
        <MaxParallelism>6</MaxParallelism>
        <Model>
            <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
                xmlns:sql="urn:schemas-microsoft-com:xml-sql">
                <xs:element>
                    <xs:complexType>
                        <xs:sequence>
                            <xs:element type="row" />
                        </xs:sequence>
                    </xs:complexType>
                </xs:element>
                <xs:complexType name="row">
                    <xs:sequence>
                        <xs:element name="RefreshType" type="xs:long" sql:field="RefreshType"
                            minOccurs="0" />
                    </xs:sequence>
                </xs:complexType>
            </xs:schema>
            <row xmlns="urn:schemas-microsoft-com:xml-analysis:rowset">
                <RefreshType>1</RefreshType>
            </row>
        </Model>
    </Refresh>
    <SequencePoint xmlns="http://schemas.microsoft.com/analysisservices/2014/engine">
        <DatabaseID>123</DatabaseID>
    </SequencePoint>
</Batch>

remaining the question.

why the large semantic model was not compressed as expected after refresh ?