This greatly overstates the benefits of UUIDs, and ignores the myriad ways in which they demonstrably have poor properties in real systems. I've worked on several large systems designed around UUIDs at scale that we had to later modify to not use UUIDs due to their manifest issues in practice. And then there is the reality that v3/4/5 UUIDs are expressly prohibited in some application contexts due to their defects and weaknesses.

Also, sequence generators are a non-problem in competent architectures, since you can trivially permute the number such that it is both collision-free and non-reversible (or only reversible with a key).

It is still common to use structured 128-bit keys in very large scale databases, and it is good practice in some cases, but these are not UUIDs because the standardized versions all have problems that can't be ignored. This leads to the case where there are myriad non-standard UUID-like identifiers (in that they are 128-bit) but not interoperable.