In iOS' Settings you can specify your preference to use bold text. This can be checked in code in a couple ways:
1. isBoldTextEnabled in UIAccessibility: https://developer.apple.com/documentation/uikit/uiaccessibility/isboldtextenabled
2. legibilityWeight from UITraitCollection: https://developer.apple.com/documentation/uikit/uitraitcollection/legibilityweight
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Your iconography should support Bold Text too. One way of doing it is by creating custom symbols (and specifying weights for it) to work with them as you would with regular SF Symbols. How Creating custom symbols: https://developer.apple.com/videos/play/wwdc2021/10250/
SwiftUI has equivalent accessibility modifiers for some of UIAccessibility's properties in UIKit. Same basic concepts apply. Label: https://developer.apple.com/documentation/swiftui/view/accessibilitylabel(_:)-9ek2h Value: https://developer.apple.com/documentation/swiftui/view/accessibilityvalue(_:)-8esl7 Traits: https://developer.apple.com/documentation/swiftui/view/accessibilityaddtraits(_:) Hint: https://developer.apple.com/documentation/swiftui/view/accessibilityhint(_:)-3i2vu

Sometimes we may fail to convey to the user of things changing on the screen in a perceivable way. Toasts and similar should be announced. We may want to make clear that some content on the screen changed. Or we might want to update on progress.