The primary challenge I see is that at least in the US, government positions are often elected and termed, meaning there is no guarantee your cash flow from your government job will continue long-term. This is why you must continue to operate as a private citizen, with a government job.
The second potential issue is one of pay - the best of society can make far more in a commercial setting than in a government setting - barring corruption, of course.
For your second potential issue, I’m saying that’s the point. Nobody becomes a priest for money.
These people who become priests do so for other reasons and they largely want to exit the commercial economy. That’s the type of people government should be made of. Under this system pretty much 100 percent of politicians wouldn’t have even become a politician.
Since we are talking about political leadership at the highest levels (not pastoral local municipalities), a good comparison with priesthood would be the Vatican. Even in priesthood, when there is concentrated power over vulnerable populations, we can find: wealth hoarding, money laundering, collaboration with organized crime, and protection of rampant sexual abuse. For hundreds of years. This suggests to me that the issue is hierarchy more than it is quality of those who reign over us.
Here's my hot take: politicians should be paid a lot of money, and in return they should be subject to limits on how they can invest, if they can invest at all. Remove the incentives that cause corruption and attract talent. I think it's a bit naive to say that public servants need to be earning a meager salary. Underpaid people don't stay in their roles very long.
The first point is true of most employment, unless you're one of the ~10% of US employees with a union contract. Your paycheck is always subject to the whims of your employer.
I don't have a great solution for the 2nd issue you pose though. Raising the pay of elected officials is often politically unpopular, but you're certainly right that one makes more in the private sector than as a junior congressperson.
Yes and no - if you lose your job at Apple, you can go down the street to Microsoft. If you lose your elected government job, you can't run again for years. Meaning, you have to switch from being a government employee back to being a commercial employee.
The second potential issue is one of pay - the best of society can make far more in a commercial setting than in a government setting - barring corruption, of course.