OpenSSL doesn't follow semantic versioning. This is not a simple version upgrade. They knowingly broke the API between 1.0 and 1.1 and it can require substantial changes. They also refused to provide a compatibility shim to make it easier for developers to migrate.

This is not a Debian problem. This is an OpenSSL problem where they forced each upstream program author to make changes in order to upgrade. You'll have to wait for each upstream program author to update.