The Holiday Special is canon. Fite me 😆

It’s media / art.

You’re allowed to enjoy the parts you want to enjoy without validation from others.

Hope this helps

Yes, it's both too messy to be coherent, and too coherent to be a set of disjoint histories that share some universe.

There are many fun stories in it, but don't expect all of them to be fun or to have a real sequence. But if you really want coherence, you can't jump over the cartoons (Clone Wars and Rebels).

That said, if you have watched the OG trilogy, Andor is a must see.

There certainly isn't a 'grand idea' for how the universe looks. Even the most recent trilogy didn't seem to have a grand idea of what itself was going to portray. It fees like Disney is looking at the IP on a yearly or quarterly basis, and not where it needs to be in 5 or 10 years.

My enthusiasm for the IP has been completely destroyed at this point; and I'm not the only one.

Short answer, yes it is a mess.

Long answer is there have been two main structured and officially recognized and separate continuities (I'm leaving out oddballs like really early Marvel Star Wars comics since those were dead ends). Both main continuities recognize the original and prequel trilogies, however the first one, the original EU was essentially everything from the first Thrawn book in 1991 all the way to the material put out in 2014. Some of this old material is still being republished by Disney, but it is under the "Legends" banner to make it clear that it is not part of current canon.

The second continuity is the Disney reset which happened in 2014. As said above it recognizes the original and prequel trilogies. It also recognizes The Clone Wars and Rebels CGI cartoons. Everything else up to that point was thrown out the window and Disney essentially started over. A number of characters, races, events, and other material that was originally in the EU has been adapted back into the Disney continuity, but it has been remixed and reworked- this means you can't make definitive inferences that just because one thing from the EU is re-canonized, that other unseen elements also are. All of the live action shows like Mandalorian, Andor, Ashoka and all the Disney made side movies like Solo and Rogue One all exist inside the Disney continuity.