Progressive Web Apps run directly in a web browser and do not even need to be installed. The problem is that Safari is so far behind or so limited in many aspects, these apps cannot run as expected or cannot have the functionality users would expect. Apple will not allow other web browser engines to be used on iOS, so all customers are forced to use an inferior one. Even during Microsoft's monopoly, customers could freely install different web browsers.
As someone that has years of experience developing Windows, Android, iOS, and Progressive Web Apps, I can say without doubt that iOS development is the worst experience I have had as a developer. Apple is one of the most developer hostile, needlessly complicated environments I have had to work with. Apple seems to believe that it is a privilege to have permission to create apps for their platform. In reality without all of the apps that developers have created for iOS, it would just be another Blackberry (which was supposedly more secure than iOS).
Apple promotes the walled garden as a shield that protects customers from malware and spying. The truth is that it provides limited protection from malware. To bypass this shield, hackers simply need to pay the entrance fee (Apple Development Program fee) and then they are free to create whatever malware/spyware they want. They just need to get it past the reviewers, which happens on a regular basis. The walled garden is engineered to strictly control money and profits on the platform. Any good developer stepping outside of this money control is severely punished. It's disturbing how badly and disrespectful Apple treats developers.
The walled garden also causes major complications and costs for app development for small, honest developers.
Developing Progressive Web Apps is a much more enjoyable and liberating experience. There are still many limitation in what can be done within a web browser, but avoiding the nightmare of native iOS (and Android) app development is a enormous positive. Allowing iOS users to choose a better web browser would really help drive this technology forward, but I seriously doubt Apple will ever change their stance because it would require them to give up control of the profits.