Well, you did forget when that standard was established. Krita’s development started 25 years ago, so there was no industry standard. But as I said, I start to understand, why an eraser tool is or could be needed.
I find it interesting, that krita is even compared to the industry standard, as it has limited resources. But please do not think, that krita has, even in the slightest, the power to compete with those programs when comparing the development force. The development is restricted to those who are contributing, and that is restricted to the donations.
If you want that features are developed faster, please consider donating, as the krita foundation can then hire a developer especially for features, the users want.
And don’t fortget to vote for the feature request. Feature request