If you're starting from the perspective of a native app developer, you're absolutely correct. However, most startups are going to be websites/Electron/CEF apps. It's much easier and cheaper to write-once-ship-everywhere with an ugly React UI than it is to jump through the hoops of writing special-snowflake versions for every OS under the sun.
It's basically negligent to insist on native apps, if profitability is your goal. I love native interfaces too, but the staunch belief in businesses being a "good native citizen" is a dead meme. It's cart-before-horse logic, we don't ever see anyone commit to the idea and reap real rewards. Native platforms punish you for playing by the rules.
It depends who your application is for. You obviously think building an application is about maximizing your profit, and your users are just a means to achieve that. If you were approaching your application from a “what’s best for my users” angle you might make different choices.
If you are running a business with limited funding (which is most businesses), then your primary need is to seek profit in a world where profit is often never achieved at all. Otherwise, your business ceases to exist, along with your app. Sometimes that does mean emphasis on strong design, which I’d argue means delivering a great experience to your users rather than a native or non-native design choice. Other times, you’re serving a demographic that doesn’t care so much about that, and your focus is on functionality above all.
It's basically negligent to insist on native apps, if profitability is your goal. I love native interfaces too, but the staunch belief in businesses being a "good native citizen" is a dead meme. It's cart-before-horse logic, we don't ever see anyone commit to the idea and reap real rewards. Native platforms punish you for playing by the rules.