Best way to work with hierarchical data in Mysql for a system with constant register in the hierarchy

Question

I have a table where I store user registration where each user was indicated by another user, so I keep a column ID and a column PARENT_ID.

There are 2 ways to work with hierarchy in Mysql, are they:

1. Adjacency List Mode
2. Nested Set Model

I had chosen to use in my project the Nested Set Model, for having greater performance in the queries, not needing to generate a QUERY for each node when I fetch all hierarchical entries. No Nested Set Model I saw only one drawback: you need to update the values LEFT and RIGHT of all registrations when a new registration is made.

Doubt:

What is the best alternative? Lose performance when registering the user, and I will need to give a UPDATE in each register(+50000) using the Nested List Model or lose performance at the time of consultations using the Adjacency List Model?

In that case, I should use the Adjacency List Model since registrations are dynamic?

The Nested List Model would only be useful when the hierarchy is static, such as product categories?