Here’s my take on it… an annulment is kind of like a legal proceeding. We hope that, by and large, they come to the right judgment, and we trust that the Holy Spirit is working through the members of the tribunal. And I think their judgment is legally binding.
Kind of like in a criminal trial… O.J. was found “not guilty” by a jury, and that’s official and binding. Even if a lot of reasonable people disagree and think he was guilty, he can’t be re-tried for the same crime. In point of fact, he was either innocent or guilty, and only he and God know for sure. But according to the law, he is not guilty, and is thus free from any of the possible legal consequences of the alleged crime.
Back to annulments… I suppose in point of fact the marriage was either valid, or not valid, and that may or may not correspond with the judgment of the tribunal. Only God knows for sure. But the best we can do is trust the tribunal, and not try to second-guess them. Just as we don’t try to second-guess when people are married - you would never say “yeah, they got married in a Catholic church, but I bet it wasn’t really valid… it’s just a pretend marriage and they’re really living in sin”. You operate under the presumption that the sacrament was valid, until legally found otherwise by the proper authorities, i.e. the annulment tribunal.
Does it seem like there are an awful lot of annulments being granted? Yes. So does this mean some of them are being granted wrongly? Perhaps. But I think there are also a lot of invalid marriages happening these days - so many people are just not open to God’s grace for one reason or another, and are just not properly disposed to enter into the sacrament. And it’s not necessarily something that’s going to be visible on the level of still having a connection or an attraction or chemistry with someone.