I've had the opposite experience, every single one works great first try but with most operating systems releasing at least twice per year these days. As such I haven't found the need to have a big list of options that I'll install more than once or twice anyways. That combined with UEFI there isn't much process to make USBs bootable.
Persistence always seemed cool on these types of tools but similarly I've never needed a persistent USB I'll boot from often enough to make the persistence more of a benefit than a burden.
I find that it is reliable for Linux and Windows. It is easy to copy an ISO onto a flash drive, it can store multiple ISOs, and those ISOs can be updated without overwriting other data on the drive. This means application installers and data backups can be stored on the same drive, making it a very convenient recovery drive.
As for other operating systems, they seem to boot partially but the boot process ultimately fails when they try to access the drive directly.
