EndeavourOS is very good for newbies, but it’s certainly not for everyone.
It’s not for people who just want things to work and are not interested in learning how their OS works. It’s great for newbies who are curious, interested in how their OS works, not afraid of using the terminal, willing to spend hours reading documentation and forum posts and, most importantly, have a DIY mindset and are willing to break and fix things on their system. This is crucial for having an enjoyable experience with EndeavourOS.
It is probably the best distro for gaming, assuming that what I wrote above is satisfied. PC gaming is already for the technically oriented people, normies typically just use gaming consoles.
Having a backup is certainly a good idea, not because of any “updates breaking something in your system” but because all hardware fails, eventually. So when your hard drive fails, you’ll be very happy you made a backup. Timeshift snapshots, however, are not backup, they are snapshots. Having snapshots is certainly not necessary, most issues with updates can be easily fixed, typically quicker than restoring a snapshot. In fact, I find snapshots to be a waste of space. Also, whenever you restore a snapshot, you miss the opportunity to learn what went wrong, how to fix it, and more importantly, how your OS works.