Yeah, I keep an G4 PowerBook around to watch DVDs on and run PowerPC Mac abandonware... it can surprisingly do a lot. IRC, Hotline, BBS, Gopher, etc. A YouTube channel called "Squeezing The Apple" has a lot of videos showing the use you can get out of an old PowerPC Mac.

Channel here: https://www.youtube.com/@squeezingtheapple6990

When you max out the RAM (around 2GB) and put in a solid state IDE hard disk they can be useful. I occasionally use mine as a distraction free writing tool.

Other than abandonware (old games for example), they can't do anything a modern Mac couldn't do, so I wouldn't go nuts finding and buying one of these but if you have one laying around, and have the parts you need for an upgrade these old Macs can be fun.