You’re planning to migrate to SQL Server 2022, and you want your databases to be faster after the migration.
This is NOT a blog post about how to migrate – that’s the same as it’s been for a long time. Go build the new 2022 servers, and use log shipping or database mirroring to sync the old and new servers. (I’m not a fan of using Distributed Availability Groups to do version upgrades. You can, but it is a heck of a lot of moving parts to set up for a one-time migration.)
This is a blog post about what to do