In the original subnet vision, each subnet validator was required to validate the primary network as well by staking 2000 AVAX. It was assumed that validtors of the primary network would eventually expand their operations to validate subnets as well as a source of additional revenue or perhaps as primary source of revenue as APYs for validating the primary network would decline over time.
However, with ACP-77, validators of subnets (L1s) no longer need to validate the primary network. In effect, there needs to be a sustainable way to incentivize primary network validators over the long term. What is the plan to do so?