What's to stop someone you don't trust getting into government or banking after those institutions gain extensive access to your information? (Maybe the safeguards are stronger where you live than where I live, but are they strong enough and will they remain in place?)
Those institutions already have extensive access to my information. I trust my bank with my life savings; I trust the government with my retirement and old age medical care. I can certainly trust them with my text messages. Sure there are vulnerabilities, but that's what insurance is for.
My last comment was sloppy and I agree with much of your reply. However, the governments that serve their populations well do so in virtue of their structures and office-holders, both of which change over time.
My concern is that any increase in already substantial state powers poses a twofold threat. Firstly, it makes future increases more difficult to oppose. Secondly, it risks falling into the hands of irresponsible future office holders.
I suggest that you wouldn't be able to trust your government with your text messages if you fell into one of the following three categories: freedom fighter, wrongly suspected of crime due to unchallengeable secret evidence and targeted for state-imposed restrictions without explanation, actual criminal (possibly under a homophobic, misogynistic or racist law).
I'm not sure about the banks, but maybe some of the above applies to them, too.
The New Zealand parliament has identified five "institutionalised checks on executive power". (They are a codified constitution, an elected head of state, a bicameral legislature, devolved powers and proportional representation.[0]) Only two exist in my country (the United Kingdom), neither of which is available to me, because one of our legislative chambers is unelected and (like the majority of the population) I don't live under the jurisdiction of a devolved legislature.
I don't understand your last sentence. By "insurance", do you primarily mean checks and balances? If so, which ones matter to you?