Revo Uninstaller Pro is an excellent alternative to CCleaner.

I still use Speccy and occasionally use Defraggler but as for CCleaner, Glary Utilities is my new cleanup tool. It also includes a defragmenter in it along with a huge suite of other useful tools. Also, unlike CCleaner, they don't constantly hammer you with ads or lock features behind a paywall.

Windows has it's built in Disk Cleanup utility that does most of what CCleaner does. And it already runs it on a schedule, in the background, without you ever having to do anything.

CCleaner was needed way back in the day before Windows had built in tools, but it's basically entirely redundant now, except for its ""Registry Cleaner"" which tends to cause more problems for people than it ever fixes.

And you're feelings of sketchiness are somewhat correct. In 2017 attackers had gained access to CCleaner, and injected a virus into it which Piriform (the company that makes CCleaner) distributed for multiple releases of the software. It was corrected, but it doesn't exactly reflect well.