The FAQ says:
Does a user need to set up and operate a participation node to earn rewards?
While anyone can run a participation node, not all users will have the technical ability to participate in the consensus protocol. For users who are not able to run a participation node, the Algorand blockchain offers an offline mode. When a user declares themselves offline, their account’s stake is not taken into consideration for the sortition process. This allows any user to have a stake in Algorand without requiring them to operate a participation node.
Currently, the system treats all users equally. In the future, the Algorand Foundation may propose an upgrade to increase the rewards given to online users—incentivizing them for their participation in the cryptographic sortition protocol—and decrease the rewards given to offline users.
If currently rewards for running a participant node and staking offline are the same, then what’s the point in running a participant node?