Alternatives to QuickTime 7 for making simple edits without re-encoding? (This is similar to a question I asked in 2014 but I'm hoping there are better options available now, plus we have to take the lack of 32-bit apps into consideration now.)

QuickTime 7 will no longer work in macOS 15 "Catalina" so the time has come to find an alternative.

Playback is no problem, as there are many apps that can playback videos in more formats than QuickTime 7 could.

However, one of the best features of QuickTime 7 "Pro" was that it was able to make simple edits to video files (not just trimming from the start or end, which is all QuickTime X can do). 

It also did so without re-encoding the videos, at least for .mov files.

I'm hoping to find GUI app options, rather than, say, some kind of magical ffmpeg invocation. Bonus points for being easy to use and not having an atrocious UI, but at this point I'm open to just about anything.
QuickTime X seems to be able to open a .mp4 file, trim it, and re-save as .mp4 with no re-encoding.
This was surprising to me, as the only way to Export the file is via a filetype change to .mov.
If you take other actions such as Add Clip to End..., the menu item for Save will become greyed out and you will be forced to export as .mov if you wish to save. If you Split Clip more than one time without deleting a segment it similarly prevents the save.
But this does enable easy trimming and re-saving without .mov conversion using Quicktime X.
Trim .mp4 video file:

Open a .mp4 with QuickTime Player X
Scrub to a location in the file. Use the keyboard arrow controls for frame-perfect accuracy.
Press Split Clip CMDY to cut the video into two segments.
Select the unwanted segment. Press delete to delete.

Note: You can also use the Trim CMDT command. But I find it is almost impossible to accurately set the In/Out markers without keyboard arrow controls, which do not function in the Trim UI. Instead, use Split Clip to delete each end of the trim.
Save without re-encoding

Press Save CMDS
A &quot;Save As...&quot; dialog will pop up.
Note that it is exporting as .mp4. Default value: Export As: Untitled.mp4
Rename your file and save.
Resulting format will be same file type and dimensions as your source file. Its file size should also be smaller, depending on how much was trimmed.


Export As...
Note that the Export As... menu does NOT contain &quot;pass through&quot; or &quot;original&quot; or any good option.
When you select 480p you are only able to export as a .mov file.
Use Save rather than Export, which will allow you to re-save as a .mp4.