I'm curious how each of those handles against loss of software, registration keys, username/password, or the company going out of business? I remember being concerned about the fragility of the process back when I used tapes. It backed up to proprietary media, in a proprietary format, using proprietary hardware, and proprietary software. It seems quite silly for a backup process to require backing up software and data using some other process. I actually still have the tapes, but no way to read them, or to even tell if they're readable. Hence the attractiveness of a simple copy, there's nothing needed for a recovery other than an an operating system.
It would be nice to have something that produces a copy like Robocopy, but before copying a changed file, the old one is moved to a folder named with the current date. I doubt I'm the first to think of that, anyone know of software that does anything similar. Since most people rarely change old files, it wouldn't use up that much more space.
They are each going to be different in their abilities - Acronis and Clonezilla are image backups, Acronis runs on a live system, Clonezilla boots from a CD/USB stick and performs a disk image backup while the system is offline. Both bring back the entire system - OS, software, registration keys, etc. They are "images" of the actual disk (for practical purposes). Furthermore, Clonezilla is free and opensource.
Backups and archives are different things with different requirements. You can mix the two, and that is where the issues you mention come into play. I have changed my offsite backup provider several times over the years, and I could move tomorrow to another one if I need to. Same with any backup software - just start using the new one. It's protecting my current set of data (my Backblaze account only stores 30 days of changes).
Archives are long term, and then the issues of permanence and accessibility come into play. However, all my archives (30+ years of images and documents) are also on my live system. IF, if I archived and purged old data, like pictures from 30 years ago, then long term accessibility is a concern - like your tapes from years ago. But as it stands, for the data I am collecting, local disk storage is cheap enough that I can basically keep everything. In the 80's, I had 2, 20MB drives. Today, I have 24TB on my NAS (4, 6TB drives), and I can buy a single, 22TB drive on Amazon for a little over $350. Amazing!
Back on subject, I have chosen Amazon Glacier for long term offsite storage. Amazon probably isn't going out of business anytime soon, but if they did, I'd find another place to store my archives.
The tools I listed (and Synctoy is an fancy, GUI based robocopy) allow me to protect individual files by making copies (what you're doing with robocopy), but also protect machine state from when bad things happen - bad/failed upgrade, virus, corruption, drive failure, etc.