Moving your YouTube subscriptions to a new account isn't built into the platform as a single "click," but you can do it efficiently using a few different methods. 📥 Method 1: The Official Google Takeout (Bulk Export)
The most efficient way to handle hundreds of channels at once is with a dedicated browser extension like YouTube Subscriptions Transfer or Subscriptions Importer for Youtube. Moving your YouTube subscriptions to a new account
Review of YouTube Subscriptions Importer: Copy Subscribed Channels to Another YouTube Account not just feeds.
Note: This moves the channel , not just subscriptions. Use this only if you want to consolidate identities, not just feeds. Moving your YouTube subscriptions to a new account