width: 200px;

24px Font Size Texts

Conclusion

1. iPadOS 13+ intervenes against the CSS zoom property. WebKit zooms font size reversely to keep texts unzoomed.

2. -webkit-text-size-adjust: none; can be used to disable the intervention.

3. -webkit-text-size-adjust: none; only effective when zoom style node is contained by both font size style node and text size adjust style node.

4. The intervention is disabled when users "Request Mobile Website".

Reference

1. CSS Zoom does not work - iPad OS (v13 - latest) Safari (StackOverflow)