As someone who deletes or moves resurrected posts, many times I click on the member who was quoted and they haven't visited in years. If it's an 'old' thread from 2020, chances are the regulars who contributed are still around, but still also chances are the OP was a 'one and done' and hasn't been back since.
Some of the regulars go back much further and are still here, but you're reentering a conversation that they had many years ago. Imagine somebody new dragging up a conversation you had with friends 5-10 years ago. You wouldn't even remember it, but the new person just read your convo and expects you to jump right back into it. They then need to go reread the advice the gave someone else to see if it even aged well, or relates to you.
It's also against common etiquette to steal someone else's thunder. They were here for their problem and you've made it your problem by joining their thread.
It's best for all to start a new thread with your issues/questions, and tag anyone you feel may help, be it a regular or an OP. Anyone still around will see the mention and jump in if they have thoughts. Anyone not around won't see it, and no harm done that you mentioned them.
You can always copy/paste the URL from the discussion you viewed into your post for context, and to jar everyone's memory who was part of it if they're still around.