Lenovo X1, Fedora 38 Cinnamon, 8gb mem, 512gb ssd.
A couple of days ago, I tried to recover to a previous Timeshift version of my system. I made no changes to Timeshift with the intent of putting the previous version back to where it came from and overwrite what I was currently using. After clicking "restore", all appeared to go well and there were no errors indicated. It proceeded to reboot through the grub menu without issue. However, reboot sticks at the Fedora logo and the whirling circle and proceeds no farther. I subsequently rebooted with a live usb and tried the same process with the last Timeshift instead of the one previous to it that just failed. Same result. Is there any other alternative but to reinstall the OS?

You could always go back to your clonezilla or rescuzilla backup image. If you have one.

Not helpful at all - I doubt anyone using a default Timeshift backup would take complimentary full backups.

@will41, AFAIK Fedora doesn't support the required subvolume structure that Timeshift expects for btrfs; are you using btrfs ?. I haven't done a clean install in a while, but I suspect Fedora defaults to btrfs these days. If so I'd reckon you would need to re-install unless you have a g00d understanding of btrfs subvolumes. It's not just the (system) data, but the bootloader and initram setup as well.
Personally I'd just re-install to ext4 and re-setup Timeshift - much less opaque, and should work as you expect.

Timeshift is not, and does not claim to be, a system backup. It is a useful change regression tool that complements a real backup solution. The same can be said of the pure BTRFS snapshots, they do not capture an entire system image.

FYI: the only backup system that I have trusted that came WITH a system was sysbackup on AIX, and I backed that up with ADSM backups to a remote server. When it comes to backups of critical systems, a belt & suspenders approach is the minimum! I often back up only home and data partitions on my laptops, because I ENJOY reloading from scratch. If a desktop or laptop held CRITICAL data I would image it to rotating media regularly,

@syg00, My installation was ext4 and Timeshift was set to use rsync. Also, following the first failed recover using a working system, I booted with a live usb and tried again to recover a different backup in Timeshift. Same failed result.
@wpeckham, My understanding is that purpose of Timeshift is just as I tried to use it; to recover to a known working system when you are having problems.

At this point, I have re-installed and I will re-think my backup strategy. Thanks for the comments and suggestions.

I'm surprised an rsync based restore failed - if you still had the environment available might have been worth a bug report.

On the more general question of what's a (or what to) backup, I'm a great believer in transparency. For me that largely means plain rsync. No GUI, no hardlinks, no "helpful" utilities to save disk space that is trivially cheap these days. That also for me means no system backup - I can re-install what I need in the time I need; the O/S is a commodity, what matters is my data.
I keep all my important data on btrfs, and I am a huge fan of snapshot - from mainframe days. But it is only the source of my backups, not a backup in itself. The paranoia level is directly proportional to the amount of data you have lost in the past I find.