If you mean block all network traffic that isn't in the trusted zone then sure. But disabling features you personally don't like isn't a good security practice.
Maybe I wasn't clear. First I described a somewhat common practice in corporate settings, which is ostensibly motivated by security policies. Then I described my personal preference, which I motivated with resource consumption and performance factors.
I did not say that the corporate practice is a good one, I just brought it up as an example to refute the suggestion that limited web browsers are incredibly unusual.
