In anonymous systems, where we don't use real names, your "handle" has an "age". That becomes your most prized possession.
I have a reddit account thats over 12 years old. I have left the posts/comments open. That means, my "post history" becomes a way to advertise my skills. I can reference comments from a year ago or 6 months ago about a certain topic to show how I handled something. That does have an effect on people.
As opposed to a random 1 day old account. No one takes them seriously, I guess the same is here as well
No one takes a 12 year old Reddit account seriously either. It's not a platform you can take anyone seriously. The biggest trolls have 12 year old accounts.
Be extremely careful with that account then, because they ban accounts for the most minor things now. Stuff like posting evidence disproving something the moderator agrees with. And they ban your account from the whole site, not just from that subreddit any more. Automated algorithms also ban accounts for reasons that don't make any sense.
So if you're using your account to advertise yourself and look for jobs, I'd use it only for that. All off-topic discussion should be on a different account with a different physical device and IP address (reddit checks these things and cross-bans) that have never interacted with your main account.