why does textedit keep crashing?

You are welcome.

With respect to your EtreCheck report, you appear to have multiple, so-called "cleaner" applications on your Mac, and history over the years has shown that these may present you with legitimate files (even inside an application bundle) and trick you into removing that content, which would then break the application. My recommendation is to follow the vendor's concise instructions and remove those "cleaner" category applications.

MacOS already has built-in security so you don't need to add any products for that purpose, and frequently those products also interfere with normal application and operating system behavior.

TextEdit may be continually reloading its last application state (crash), so to break that chain, launch TextEdit while holding down the shift key. Only do this immediately following a crash and not for normal TextEdit quit.

I'm curious as to what you mean by "bossy"? I use Ghostery (the free version) and am very happy with it.

I don't see this as having been suggested yet: boot into Safe Mode according to Start up your Mac in safe mode - Apple Support and see if the problem persists. Reboot normally and check again.

NOTE: Safe Mode boot can take up to 10 minutes as it's doing the following; 

• Verifies your startup disk and attempts to repair directory issues, if needed

• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)

• Prevents Startup Items and Login Items from opening automatically

• Disables user-installed fonts 

• Deletes font caches, kernel cache, and other system cache files

Are you yet at 11.3.1?

Run Etrecheck to see if something in the background is making problems for TextEdit. Do not use any optimizers that mess with the system cache.

https://discussions.apple.com/docs/DOC-250002463

First, First, there is no reason to ever install or run any 3rd party "cleaning", "optimizing", "speed-up", anti-virus, VPN or security apps on your Mac.  This user tip describes what you need to know and do in order to protect your Mac: Effective defenses against malware and other threats - Apple Community.  

There are no known viruses, i.e. self propagating, for Macs.  There are, however, adware and malware which require the user to install although unwittingly most of the time thru sneaky links, etc.   

Anti Virus developers try to group all types as viruses into their ad campaigns of fear.  They do a poor job of the detecting and isolating the adware and malware.  Since there are no viruses these apps use up a lot of system resources searching for what is non-existent and adversely affect system and app performance.

There is one app, Malwarebytes, which was developed by a long time contributor to these forums and a highly respected member of the computer security community, that is desshoigned solely to seek out adware and known malware and remove it.  The free version is more than adequate for most users.  

Also, unless you're using a true VPN tunnel, such as between you and your employer's or bank's servers, they are useless from a privacy standpoint: Public VPN's are anything but private.  

That being said, like VikingOSX said you have a lot of "cleaning" apps installed. One in particularly, CleanMyMac, is considered akin to malware by many of the experienced contributors in these forums.

You should uninstall all of the cleaning apps according to the developer's instructions.

Also you have many ad blocker extensions for safari. One should suffice and will make browsing a bit faster.

I don't know how frequently you reboot or shut down but doing so does clear out many temporary system, font and cache files.

EtreCheck would not provide an answer, but those here that review the posted EtreCheck result can determine if you have something installed that is causing issues.

Use the Additional Text tool on the bottom tool bar to post the full EtreCheck Pro results:

TextEdit should just open RTF and plain text documents without any subsequent fuss. It cannot open Pages documents.

Pages can use specific characters in the Find/Replace panel:

\n = newline and will find paragraph marks which are also newlines

\t = tab

\i = line feed or soft return (shift + enter)

With View menu > Show Invisibles on, you can select any character to make it your Find character, and then visit Pages > Edit menu > Find > Use Selection for Find. That preloads the character so that it populates the Find field when the Find tool is launched. You can also select the Find field, and press control+command+Sparebar to launch the Emojis & Symbols (character viewer) panel, and place any character found there in the Find field.

TextEdit allows find-replace features that are not in Pages.

What "find-replace" features are not in Pages?

However, that is irrelevant to the problem.

I'm at that system software. I emptied all the caches yesterday

What in the world would that solve? It might make your Mac run slower until it rebuilds the cache, but it won't stop something from crashing.

I thought Malwarebytes IS malware.

I consider it that since they started installing a kernel extension and doing things it wasn't originally designed to do.

It started out as a very good Adware removal tool. Now, in addition to that, you get the standard AV crapware with it.

You would normally consider that to be a Trojan horse, but when it became MBAM, they never advertised it solely as an Adware Removal Tool. It is only its historical roots that give it any credence.

You should only ever require the use of an Adware Removal tool once in your life. If you fall for the scam a second time, nothing will help you. You should just stay off the internet.

Because of that, I only suggest using Etrecheck to remove Adware.