Hi Wannano, Thank you for your interest in the Catholic faith and also for your patience with my impatience, which is a fault of mine.
First, when the priest is sitting in the confessional, he’s not just some man we’re talking to. He is standing in for Jesus during that time of confession. So we are actually confessing to God as you say.
Second, the priest in this role harks back to Matthew 18:18 when Jesus is giving his disciples the power of binding and loosing sin:
Amen I say to you, whatsoever you shall bind upon earth, shall be bound also in heaven; and whatsoever you shall loose upon earth, shall be loosed also in heaven.
So, the priest has this power, conferred by Jesus.
We tell the priest our sins.
The priest has the option of asking a couple more questions so he fully understands the situation, to make sure we are truly repentant and are resolved to avoid the sin going forward, although often he doesn’t need to ask questions.
Having made sure we’re repentant, the priest then has the option of giving us a little bit of advice to help us avoid sin going forward or to gain a little bit of spiritual wisdom. Again this is an option, not required.
I would note that “backintheday” a few decades ago you were much more likely to have a priest admonishing you in confession much like the OP noted. it was not uncommon at all. Nowadays in USA priests are generally a lot milder, so one of them being harsh stands out (unless the priest is a member of certain ethnic or nationality groups known to have tougher priests).
Then the priest absolves us using the power given him by Jesus, and we’re done.
Jesus would not have given this power to “mere men” (his disciples) to hear and absolve sins, if He didn’t think we could benefit from having it pass through that channel. You see all the issues people have on this forum about talking to God directly - people are not sure if He’s listening or answering or what He said or sometimes people think God is sending rather odd messages. But when you are talking to a human priest, then there’s much less room for “not hearing anything” or having a misunderstanding. And you have certainty that you were “heard” and responded to.
Now we all have a confession once in a while that goes haywire and the priest really didn’t seem to be on the same wavelength with us, but that is rare. I go to confession about twice a month, usually to a different priest each time as I go to many different churches across several states. I’d say 95 percent of them are good and the priest is helpful and sometimes I get really good guidance that I remember for a long time.
Just my two cents on it, I hope this is helpful to your understanding.