Why Signal doesn’t have web client?

I’ve read about E2EE (end to end encryption) of Signal in web clients on a Signal Community discussion forum, and wonder why they say that the browser is insecure for E2EE and native apps are secure.

I think the security issues for clients are the same. It can be harder in various systems based on their security polices, but all of the clients are prone to various attack surfaces like MITM, viruses and rats and other malware. And something more important they emphasise is the delivery for javascript files, but doesn’t that use HTTPS? I guess if anyone could break the HTTPS security they can do anything more dangerous than what we think about.

Actually, we want to develop some chat service like signal with a web client, but this article made us confused. Should we ship a web client or not? Please explain this.