Elements 2023 and Lightroom Classic

You can safely delete your prior versions of Elements.  Each version is a separate installation.  The catalogs that you have used with each version do not get deleted automatically, so you would have to delete them manually.  They do not take up too much room and can be used as backups that can always be converted again if need be. 

My only caveat to deleting prior versions is that occassionally features get deleted from the program or substantially changed.  The one that grabs the attention of many users is the Organizer's Slideshow feature that operates in an entirely new way from versions prior to Elements 2018.  If you prefer the prior version's feature, there is no harm in keeping it.

@janeh88919911 said:  I did manage to get camera raw version 10.3 into my old elements but it still won’t add Nikon Z50 files to the organizer. The Camera Raw version needed is only 9.1 but Elements 2018 didn’t ship with that version.

I think you are misinterpreting the Camera Support page.   Your Z50 camera requires ACR 12.1.   It is Lightroom version 9.1 that is required to support the camera.  Lightroom is built upon the same technology as ACR but doesn't use it as a plug-in.  This is why Lr can open your Z50 files but Elements 2018 cannot.  I think you may be able to upgrade your current ACR to 12.1 but I'm not sure.  I'll try it out later if you really want to know.

@janeh88919911 said: My understanding is the new version of Elements 2023 doesn’t have camera raw at all……….that you have to add it separately. Which in the long run may allow it to always be able to be updated.

That's not quite accurate.  Yes, you have to download ACR separately.  But that is only because Adobe has chosen to make the program downloads smaller and save computer space for those users who do not need ACR at all.  Based on past history, Elements will update ACR once or possibly twice during the product life.  It will generally not update the ACR version after the following year's version is released.  (But the workaround will work for some later ACR versions.)

@janeh88919911 said:  I have a large catalog. I am willing to try the trial version to see if it works if I can bypass transferring the catalog. Do you have a suggestion on how to do that? 

When you first open the Organizer in Elements 2023, you will be prompted to update/convert your current (2018) catalog.  You should say yes.  A copy of your old catalog will be made and renamed with a -1 suffix.  You will be able to work with that catalog again in Elements 2018, but you may need to look for the renamed catalog in the File>Manage Catalogs dialog.

So, bottom line, it seems that the problem you were having relates to the fact that your camera's raw files are not supported by Elements 2018.  Upgrading to Elements 2023 will solve that problem.

A Lightroom subscription will constantly upgrade the version of ACR that is available for that program.  Elements does not.  However, there is a workaround that will allow you to upgrade a recent version of Elements to the latest version of ACR.  See this article. 

But I'm not sure this is the problem you are describing in your workflow.  That is why I suggest you download the free trial and see for yourself.

@janeh88919911, it's not clear what your question is asking.  You can download a free trial of Elements 2023 and see for yourself whether it meets your needs.  As far as I know, nothing has changed in the way Elements and Lr play together.