256 GB Storage (240 GB in use).
^^ This is the problem, right here. ^^
Runaway processes and low free storage space are common reasons for Macs to run slow / beachball.
It is possible there are processes running in the background that are using significant resources. Check Activity Monitor, CPU tab (sort by % CPU) and Memory tab (sort by Memory) to see what's running hard.
Activity Monitor User Guide for Mac - Apple Support
Confirm that you have sufficient free space on your internal storage – based on your post, you DO NOT. The absolute minimum is ~20-25 GB free space, and as a rule of thumb you should aim to have 15-20% of your total internal storage as free space. Terminology is important here – free space is not the same thing as available space. The one that matters is Free space, but what macOS shows in most places is Available space. Available space includes both free space and ‘purgeable’ space, the latter comprises system caches, snapshots and other data that macOS can delete if it decides more free space is needed. However, there is no way the user can force those data to be purged.
The place to check how much Free space you have is in Disk Utility (in Applications > Utilities), by selecting the main container disk below the drive itself (you may need to select View menu > Show all devices to see it). For example, on my M4 MacBook Pro, the Storage settings pane and Get Info on the internal drive show 1.24 TB of Available space, whereas Disk Utility shows there is 1.15 TB of actual Free space, 90 GB less than ‘available’. Although 90 GB is a small fraction of my 2 TB internal storage, that would not be the case with 256 GB or 512 GB of internal storage.

Note that you can also see the Free space in the System Report (System Settings > General > About > System Report button, at the bottom > Storage).
Some steps to take to safely free up space:
Free up storage space on Mac - Apple Support
Optimize storage space on your Mac - Apple Support
How to free up ‘System Data’ and other st… - Apple Community