Premium is the ticket to X's payout program. It is not the audience. The 500 verified followers and the impressions are still yours to earn.
What the subscription actually buys
You do not need it for XPacts. Any public X account can sign in, with or without a checkmark.
What the subscription does is let you apply to get paid. Original Content Rewards, the program that replaced Creator Revenue Sharing, requires an active X Premium, Premium+, or Premium Business plan. X Premium Basic counts when someone views your post. It is not the plan that qualifies you for the program.
The numbers behind getting paid are on how to get paid on X.
What it does not buy
The payout program also wants at least 500 verified followers, and at least 500,000 Home Timeline impressions from verified users in the last 90 days. Impressions on replies do not count. A checkmark does not produce either number.
Bought followers, auto-follow, and a pod of people liking posts they did not read do not fill that gap. X's rules tell creators not to use tools that artificially generate follows, views, or likes. A follower who is not verified does not move the 500.
When it is worth paying
Pay for Premium if you post original work and you mean to apply for the payout program. Its first bar is 500 verified followers. A pact with an account that has a checkmark is one of those: you follow on X yourselves, and the follow is checked for a month. A pact with an account that has none is still a real follower. X just does not count it toward the 500.
Skip it if you wanted the follower count to move on its own. The subscription is a poor purchase for that. Growing the account is still replies, posts a stranger can answer, and mutual follows with people who would have followed you anyway.
That part is written up in how to grow on X under 10,000 followers.