Picasa had face recognition, basic editing, and a bunch of sorting features and ran on computers that had something like 1/50th the CPU performance.
Meanwhile modern replacements like DigiKam, Lightroom, ON1, and so on are incredibly bloated with very slow UI response even on a very powerful desktop PC.
Although Immich does at least work well, the webUI is extremely fast and loads images instantly.
I do with they had OSS'ed the code for at least the desktop app, but maybe there were licensing issues? or just no one cared.
Darktable and ON1 feel decent snappy on my ~8 year old Desktop PC.
Though it was a looong time since I last tried Picasa.
I just watched a video of Picasa to jog my memory. It seems similar snappy as ON1 with 24 megapixel raw images on my 2015 PC.