If you read closely i'm proposing government use only, where each governing body participating in the system has access to it.

You can keep compute systems down - i'm more interested in immutability and distributed nature than the trust issue of blockchain.

Then you don't need blockchain. Once you have trust among the participants, you don't need blockchain.

as i said - I'm more interested in a immutability of the whole chain, without any backdoors to modify old data because - speaking form experience - that leads to way more problems when dealing with local governments.

And the point myself and others are making is that you can get that without using blockchain. Blockchain is a specific technology that requires proof-of-work among distrusted actors for modifying a cryptographically secure distributed ledger. It sounds like you just want a cryptographically secure distributed ledger.

Isn't that why some coins are moving to proof of stake instead of proof of work? Solves the energy crisis. Idk if proof of stake prevents 51% attacks though.

Proof of stake does not offer any resistance to Cybil attack or (part time) collusion of stake holders.

In the case of such attacks the victims will find themselves in a situation that can be described as "shadow ban" - their transactions are not accepted or accepted too late, etc.

Proof of stake doesn't prevent 51% attacks. It eliminates the incentive. If an attacker controls 51% of coins, why would they attack the network? That would be attacking their own wealth.

Not if they can attack the network without anybody knowing. If an attacker secretly controls 51% of the coins (by, say, having three separate entities that each control 15-20%) and can manipulate the market in their favor by rejecting transactions that would hurt them, that's a big incentive.

seems like with state actors owning more and more of it, as well as the mining hardware that they could pull this off at some point in the future. Namely China right now.