I would encourage you to adopt iCloud sync unless you can’t allow these files to have their “truth” copy be stored online.
In the past - the cloud sync had some cases where it wouldn’t work for very common situations, but now those reservations are all edge cases in my eyes.
You can use your documents folder / desktop folder and expect everything to sync up to the cloud. This includes finder color metadata, smart tags, as well as content and normal metadata (last opened, created, size, etc...)
On iOS - the files app is somewhat basic, but I expect it to iterate rapidly as people decide how to use it and Apple adapts the layout and training so people can use the tools.
The underlying sync seems quite solid in my experience the last 2 years with improvements made each month along the way. I have about 120 GB of files stored and am delighted with the performance now that I have an always-on Mac Mini running iCloud content caching on my home and work networks. Restores of 128 GB to a full iPhone that used to take day(s) now takes hour(s) with most of the restore functional after 60 minutes. You don’t need caching, but it’s there for power users or people with slower network access speeds or worried about restores pushing them over a data usage limit.