No, an older iOS will not be supported, as the developers want to use the new possibilities that have come with iOS 17 to build a fast and memory-saving app with all the latest features. Since iOS 17 runs on all devices from the iPhone XS from 2018 onwards, I can well understand this decision for a 3rd party app to limit a new project, which the developers develop free of charge in their spare time, to the latest platform. Especially since some new possibilities have been created with iOS 17 and, if I have it right in my head, the latest Swift version only works with it.
Of course, this is stupid for all those who would like to continue using their devices that are over 6 years old, but I think 0 stars is simply inappropriate. As I said, it is an independent app that is developed in spare time and made available to all of us free of charge.