it's more important for the Hive ecosystem to grow. It generates more value.

This.

Also, USD inflation makes the HBD peg easier to maintain. The problem is that it's becoming harder to maintain because the Hive ecosystem isn't growing, it's shrinking. For the ecosystem to grow the users that are becoming discouraged, because they split ~10% of the rewards and the ~36 whales capture the rest, need to gain more of the pie - and more of the pie yet needs to be available to new onboards that extant creators will attract when their increasing attainment of rewards causes them to make posts expressing their happiness with posting on Hive for rewards.

"I don't see the point of HBD..."

When the platform arose in 2016, crypto was a new kind of money, and having a stablecoin pegged to the dollar enabled folks skeptical of crypto to have more confidence in HBD. It also facilitated using HBD in commerce, because vendors also had the same problem. Later the fact that whales had to curate posts and gain curation rewards to gain ROI on their stake demonstrably caused derangement of curation, causing trending to be filled with garbage posts whose only purpose was as a common target for whales to upvote to maximize their curation rewards as quickly as possible.

High interest savings accounts would enable whales to gain reliable, predictable ROI from saving their stake, eliminating the need for curation rewards, and eliminating curation rewards would restore curation by subjective valuation of it's quality, rather than because upvoting the most popular post enabled the highest curation rewards to whales hunting ROI.

However, curation rewards were never reduced. Rather they increased. I think authors now get ~10% of the rewards from the pool, while curators get ~60% (I don't recall the relative % specifically, but Holozor knows how to extract that data he showed me recently). Greed is killing Hive.

Edit:

"...they will have to enter the crypto world."

Yes, but CBDC's will just enslave them, not have any potential for enabling prosperity. We will own nothing, and be happy - or else. Remember?