I think it's more a case that browsers take security into account at the feature design phase, whereas other applications don't. That's actually a huge step in the right direction. Same thing with mobile OSes, which have a very preferable decision to sandbox individual applications, instead of running them with full user permissions & full user data access, like desktop OSes do.
Now, whether the browsers or mobile OSes actually are secure because of that, is a separate thing, but those are good steps to take.
Now, whether the browsers or mobile OSes actually are secure because of that, is a separate thing, but those are good steps to take.