Blockchain solves for trust. If it's just your own company then you need a reliable database, not a blockchain.
If it's a small network of trading partners who need a shared source of truth about topics of interest within their own trading network, that is the permissioned blockchain idea. In this case, miners (or "verifiers") would typically be evenly distributed to prevent any participant from gaining an unfair advantage. As @JAG points out, they might as well set the gas limit really high and block time really fast. Several Ethereum offshoots work on roughly this basis.
If you want assets that can escape the boundaries of private networks, then you need a widely inclusive network where any member of the public can validate claims. You need to account for nodes with scarce horsepower and high-latency connections. To avoid unwanted centralization, you will have to accept anonymous nodes. Probably there will be no accountability for misbehavior in this case, so you will probably introduce financial rewards and punishments in place of accountability.
You will end up with comparatively high block times and financial incentives to help ensure the network tends toward correctness and consensus even though there may be nefarious and anonymous participants with no accountability.