you only need 1.3GB of storage to run a bitcoin node and support the network !
Now running a node is easy! But the problem is that the number of nodes is impacted by the bitcoin price! When the price is on the uptrend, so-called bitcoin believers will have incentive to run a node!
How is price of bitcoin giving an incentive to run a node ? (Unless you are a miner). If you are non miner , you are not directly getting any BTC by running a node.