Actually bending hard tubing is not difficult at all. Just need to have patience and buy extra tube to practice and a tube cutter. I used a step up drill to do the ID chamfer and some sand paper to smooth out the OD edge.
It depends on tube quality and, as you mentioned, patience ... a lot of patience. For my first hard tube rig, I had big problems with Alphacool tubes from earlier series and literally wasted a whole package with pretty bad results. Even though all was done as in guides/manuals, there were some bubbles or shadowed surfaces. Good for me, it was a review sample as these things are not cheap. Later, I had better results with some other products.
Hard tubing products are now much better quality than some years ago, and I noticed it's harder to make it wrong. There are also already pre-bent 45/90° tubes in stores, so you don't have to do that on your own.
If someone plans a more standard loop and everything fits in straight lines, I still recommend 45/90° fittings or pre-bent tubes. It won't look as good as perfect bending in non-standard angles, but it takes less time and is much easier for less advanced users. I also don't think a typical user changes the whole hard tube cooling more often than other PC components. Considering it's somewhere between 3-5 years, there are not many chances to learn hard tube bending... unless someone is motivated enough that spend additional money and time on tubes.
I also see that hard tubes were more popular maybe two or three years ago. Sales of these products went significantly down in the last two years. You can see what new products are wider available and that hard tubes are more popular in sets than as separate products. Popular sets typically don't include bending tools and are based on 90° fittings.
Hard tubes are popular mainly for showcase PCs nowadays. I made mine almost only because I had review samples and vendors asked to build something that was later left as a build for review photos of other components.
I'm not saying don't bend tubes or don't learn it. It would be great to see some new builds with nicely bent tubes, so good luck and have fun with your build. I think the next one for me will be something that won't be transparent. I liked how my ITX PC looks with black tubes, fittings, and some other things, and maybe I will build something similar in a bigger form. I will need a review rig that will look good for photos. I'm just not decided what to do. My last hard tube cooling with all other components went to my brother.
