Thank you for your feedback.
In terms of setting SQL Server as the default database format, that is currently not in scope for the Access product. We have provided and will continue to provide efficient methods to integrate your Access data with SQL server, and the team will continue to develop more features that streamline the data migration experience (see https://support.office.com/en-us/article/migrate-an-access-database-to-sql-server-7bac0438-498a-4f53-b17b-cc22fc42c979)
However, the ACE database engine has and will continue to be Access’s central data storage unit.
There are new features coming soon that will improve the Access: SQL experience, and we are excited to share this news. Please stay tuned! :)