Sometimes people use varchar(36)/char(36) (or varchar(38)???) instead of native uuid for primary key.
It's an antipattern.

See

• https://www.jacoelho.com/blog/2021/06/postgresql-uuid-vs-text/
• https://stackoverflow.com/questions/32189129/performance-difference-between-uuid-char-and-varchar-in-postgresql-table
• https://itecnote.com/tecnote/sql-performance-difference-between-uuid-char-and-varchar-in-postgresql-table/