If I understand your question, yes in DPoS (Delegated Proof of Stake) witnesses validate and sign blocks of transactions to secure the network like miners do in PoW blockchains such as Bitcoin. The advantage is that witnesses don't burn enormous amounts of energy to secure the network.

Many put their trust in PoW b/c it is not directly influenced by human corruption. It is assumed that PoW is immune to that being only a mechanistic algorithm and PoS type systems are vulnerable to collusion and being "bought off" by outside influences.

You must look at the system as a whole to truly understand its vulnerability to outside influence. Decentralization is the key concept you need to understand, and how that is achieved.

Bitcoin was quite decentralized when it was mined by only CPUs and GPUs. Satoshi didn't anticipate the mining hardware "arms race" that has a major centralizing influence on who controls (and thus who could be targeted by "authorities"), making Bitcoin vulnerable once again to outside influence.

In DPoS, there are at least 11 witnesses (it's up to shareholders how many there are; there is no actual upper limit) who would need to be replaced to influence block production, and they are scattered across the globe and can be voted out within 60 minutes and replaced if the shareholders deemed them unfit and irresponsible. DPoS has far more checks and balances in its governance model than Bitcoin has.

DPoS isn't perfect, no system designed with humans anywhere in the loop ever will be. It is better than turning control over to machines that either 1) currently only implement the instructions of humans and thus inherit human flaws and shortcomings, or 2) if one day machines become capable of sufficient capacity to "manage" humans they will do so not to humanity's advantage and well being but rather the advantage of the machines. In so doing we become slaves to the machines. Even under scenario 1, who programs the machines can thus program humanity.

Another point that often goes unexplained, is what is meant by "securing the network". There are 2 aspects, both involve the same cryptography.

1. Securing the Ledger - this is what the blockchain invention accomplished. It uses cryptography to interlink a chain of transaction blocks such that as each block is verified and added it strengthens the integrity of all previous blocks.

2. Security of Account Balances - this rests primarily on the strength of cryptography. If this can be "cracked" (for example by quantum computing), EVERYTHING in our modern world would be vulnerable. All it takes is to guess the private key of a wallet address and the balance is opened for the taking. It is very similar to the guessing game the minors of PoW use, but there is no way to know which addresses have balances worth the effort to crack, and there are billions of addresses and billions of possible private key values. Have any idea what a billion times a billion is? It's such a long time it's essentially an impossible task.