Backup files into a single Container/Archive/Image/etc?

I have some folders that I want to keep backups, but inside there are hundreds of thousands of files so I would like to repackage them in some form of Container/Archive/Image as the title says. Cause it's much easier moving a single file in another storage cause every time I do individual files it takes forever.

So far I tried compressing an 8gb folder with lots of small sized files into a rar archive. It's bad in practice cause every time I need to delete or add files and folders it repackages the whole archive and takes forever...

Then I thought of placing files inside an iso. I tried ultraiso and then added files alto create 100gb file. It took a long time (almost one day) to create and also some files and folders had special characters and we're not includes inside the .iso. I tried a different folder with imgburn creation tool and then I got a warning that some structures exceed the 8 folder directory limit supported by iso standards

TLDR; do you have an appropriate contair to recommend that I won't run into any troubles and can make backups of folders with lots of files inside without running into issues with unsupported characters/folder srructures and standardized limitation, as well as being able to o add/remove files into said container without taking lots of time?