A little advice about social media from someone who has been on social media since it has existed. You don’t have to argue. When someone wants to argue with you, you should block them. There is no good outcome possible from arguing on social media.
If it's someone claiming they have gospel truth about an opinion, then yes, they're best blocked. That said, I do feel it's good to engage with those who have different opinions (as long as it's civil). Otherwise we end up being in isolated silos.
One good thing about Mastodon is that it doesn't allow quote-posts. This, as seen on the Hellsite, just leads to talking about the post (often with the goal of ridiculing it to third parties) rather than talking with the maker of the post.