> Haynes manuals were fantastic! Are they still popular today?

Yes, they are still popular in the hobbyist community for many cars made before a certain date. The manuals are highly accessible in the US because the public library system generally hosts the digital copies, so if you have a library card in most states, you can access the manuals online. Help support your public library!

Nowadays you can get the same factory service manual that your dealership/repair shop uses--it's all just a bunch of digital PDFs. In my experience factory service manuals, at least for GM cars, are orders of magnitude better than a Haynes manual.

The paper 3rd party manuals went down the shitter over the course of the 00s but realistically for any model that new or newer you can use Youtube for the procedures and the manual (haynes or otherwise) as a desk reference for torque specs and whatnot.

For VWs and BMWs, at least, the (Robert) Bentley manuals are considered a lot better.

Do they still end in "Reassembly is the reverse procedure thereof."?

I'm not sure about today's 2023 models but I keep a Haynes Manual in my 2011 Mazda and it is very useful.