You can compress with upx (at the cost of increased startup time in the order of hundreds of ms, which is okay for servers) and/or not include all debug symbols. Doing both usually shaves >60% off a binary.
It makes no sense for most use cases where I’ve seen it. It adds runtime costs both in terms of start-up and memory usage.
Maybe it helps in terms of binary sizes for downloads — but those are often compressed anyways! E.g. Your docker images are compressed and UPX’ed binaries in a layer aren’t buying you anything (just adding runtime costs).
Not everything uses Docker.
But one valuable reason to use something like UPX is that you can attach a crappy and thus inexpensive disk to servers that you're not using for actual storage. Compression on disk lets you load from a slow disk faster, and of you weren't paging to disk anyway then UPX doesn't have much of a cost.
But if you're on a traditional desktop operating system, UPX will increase your effective memory footprint, and force writing to swap instead of merely dropping pages. On Android, which doesn't swap, you'll significantly increase your memory footprint.
gzip probably gives you better compression ratios too.
Also, even if you publish raw binaries without an installer package, HTTP protocol supports compression. Usually quite easy to implement, couple lines in a web server config.
Nowadays disk space is very cheap, disks are often solid state with ridiculously high IOPS, but antivirus software became much worse and likely to mark a UPX compressed binary as malware.
Edit: somehow read “doing both” as “doing either”. Just ignore this.
Stripped means that the compiler does not include debug symbols.
They are completely different - you can use either or both.