Don’t move files off the Edge as your first step. Copy them, verify the copies open or import correctly, and only then consider deleting anything from the device.
The Finder instructions are a little too optimistic for the Edge 1050. It uses MTP, so it may never appear as a normal disk under Go > Computer. Garmin Express can recognize the unit and handle syncing or updates, but that does not guarantee ordinary Finder access. Garmin’s own manual notes that macOS does not detect the 1050 by default because of its limited MTP support.
It helps to separate the jobs:
For normal ride syncing, use Garmin Connect through the phone, Wi-Fi, or Garmin Express. There is no reason to hunt down the FIT file unless a sync failed or you specifically want an offline archive.
For a manual backup, close Garmin Express and connect through MacDroid or another MTP-capable file manager. Look in the device’s internal storage under Garmin/Activity, then copy the .fit files into a dated folder on the MacBook. The filenames are not very descriptive, so sorting by modification date is usually easier than guessing which ride is which.
If an activity did not sync, first copy its FIT file to the Mac. You can then sign into Garmin Connect in a browser, choose Import Data, and upload that copy. Garmin Connect accepts FIT, GPX, and TCX activity files, subject to its file-size and data limits.
For files going the other direction, @rocketexplorer5339po has the important folder right: use Garmin/NewFiles. Compatible FIT, GPX, TCX, and CRS files can be placed there. After a clean disconnect, the Edge processes the file, so it may no longer remain in NewFiles afterward. Courses are usually less hassle if you import them into Garmin Connect and use Send to Device, but direct copying is useful when that route fails.
Be careful with the word “backup,” though. Saving Garmin/Activity backs up the original ride recordings. It is not a complete restorable image of the Edge, and it does not necessarily preserve every profile, map, app, setting, or database. You can copy more of the Garmin folder for reference, but I would not blindly restore the whole folder later. Some files are device-managed, maps are large, and Garmin explicitly warns against deleting unknown system files.
If MacDroid sees nothing, check the boring stuff before changing software: unlock and power on the Edge, use a cable that carries data rather than charge only, connect directly instead of through a hub, and quit Garmin Express completely. If Express and MacDroid are both open, they can compete for the same MTP session. When finished, disconnect from within the MTP app rather than simply pulling the cable.