They would create a new topic. Just because it’s a similar issue doesn’t mean it’s the same exact issue. To be honest, the “me too” replies on topics are not helpful at all. They can distract and pull attention away from the OP or cause confusion for Support because they start seeing a lot of additional information.
I know that I’ve seen some topics get hijacked just because one of the “me too” people were more active in talking and in the end, one person was helped but OP never got a solution. So yeah, each person generally should create their own topic unless instructed otherwise (Such as how there’s the ongoing topic at How to get help from Brave support and sharing Ticket IDs for people having Rewards payment issues).