The #1 reason the web experience universally sucks today is because companies add an absurd amount of third-party code on their pages for tracking, advertisement, spying on you or whatever non-essential purpose. That, plus an excessive/unnecessary amount of visual decoration.

The idea that somehow those companies would respect your privacy were they running a native app is extremely naive.

We can already see this problem on video games, where copy protection became resource-heavy enough to cause performance issues.