Hi,
I am wondering if Lucky Patcher is still up and running and if it's still good to use.
Also, is it still popular and used worldwide?

I`ve recently used it on pvz to remove ads. Its still good to use for certain apps for sure

This was supposed to be my question ago. Some in-app purchases patching are not working in several apps not days even in modern games.

Yes, it does work well. Apart from server side purchase verification, most of the apps work more or less.
1. Download link - http://chelpus.com/luckypatcher/LuckyPatcherInstaller.apk
2. Apps which are compatible - https://flixbox.github.io/lp-compat/

One thing which works really well is modified/removing trackers and permissions.