Last time I checked (a few years ago I must say), a 10^15 URE was only for enteprise-grade drives and not for consumer-level, where most drives have a 10^14 URE. Which means your build is almost guaranteed to fail on a large-ish raid setup.
So yeah, RAID is still feasible with multi-TB disks if you have the money to buy disks with the appropriate reliability. For the common folk, raid is effectively dead with today's disk sizes.
Theoretically, if you have a good RAID5, without serious wire-hole and similar issues, then it is strictly better than no RAID and worse than RAID5 and RAID1.
* All localized error are correctable, unless they overlap on different disks, or result in drive ejection. This precisely fixes UREs of non-raid drives.
* If a complete drive fails, then you have a chance of losing some data from the UREs / localized errors. This is approximately the same as if you used no RAID.
As for URE incidence rate - people use multi-TB drives without RAID, yet data loss does not seem prevalent. I'd say it depends .. a lot.
If you use a crappy RAID5, that ejects a drive on a drive partial/transient/read failure, then yes, it's bad, even worse than no RAID.
That being said, I have no idea whether a good RAID5 implementation is available, one that is well interfaced or integrated into filesystem.
I have a couple of Seagate IronWolf drives that are rated at 1 URE per 10^15 bits read and, sure, depending on the capacity you want (basically 8 TB and smaller desktop drives are super cheap), they do cost up to 40% more than their Barracuda cousins, but we're still well within the realm of cheap SATA storage.
