Hi @AnkitJasani29 ,
I believe the site pages you created years ago were built using standard AEM, with typical AEM components and templates, and the same applies to the code structure.
When working with EDS, we use all the new features, including its own template, OOTB blocks, and site pages that are compatible with the Universal Editor. The old pages will not open in the Universal Editor. EDS also has a separate GitHub repository where the blocks are stored, whereas your old pages rely on the older components.
Therefore, it is recommended to manually create all the pages by following the EDS development guidelines.