_You_ mightn't but the last three AAA games I worked on do/did. PS5 expectes compressed files, and does HW decompression (ahem, mostly) on the fly.
Ps4 also did the compressed packages by default thing if I remember right. The upside there being ample cpu for decompression such that no compression was never fastest.
On the Windows/Mac/Linux title I’m working on now, I definitely measure a sizeable improvement to performance when loading from an uncompressed zip rather than from a compressed one. But even that could be down to the particular set of libraries I’m using to handle it.
Did you actually benchmark this? It probably makes sense in your head, but on any vaguely modern hardware it's very unlikely to actually be true because of how exponential the memory hierarchy is.
Instead, we just pack the uncompressed files together (frequently using normal zip in a no-compression mode) so that we can avoid needing to ask the OS to open and close files for us or examining the contents of a directory, both of which can be kind of startlingly slow (by video game standards) on some common OSes. Instead, we will generally cache the directory data from the zip file and just use that rather than go to disk.
(of course, the whole download/patch would all be compressed for network transfer, but files would then be decompressed during the installation process)