TL;DR: iOS Safari is more than an inconvenience for developers, it's the fundamental reason interoperability has been stymied in...

Every browser has bugs. But the sheer quantity of things that only fail in Safari is kind of baffling.

Utilizing Contentsquare Digital Experience Monitoring helps gather and rank technical errors on websites. Errors on iOS/Safari are 15% to 45% higher than traffic share, indicating a higher error rate. Yet, none of the dev teams I spoke to planned tests on iOS/Safari.

How to build web pages so they work in HTML first: starting with HTML, extra styles and features, using JavaScript.

Do not build your service as a single-page application (SPA). This is where the loading of pages within your service is handled by JavaScript, rather than the browser.
Single page applications rarely bring benefits and can make the service inaccessible.