The purpose here is to improve decentralization by making sure voting power is more evenly distributed across a smaller set of validators… with the current set approximately 10% controls one third of the network and less than 40% two thirds of the network. Having 30 validators with an even distribution can significantly improve these ratios and result in a much better Nakamoto Coefficient.
At present only 7 validators control one third of Cosmos Hub and 25 validators control two thirds, and this in a set of 180 validators. More validators do not equate to better decentralization in a Proof of Stake network. However, better stake distribution across validators do.