Perhaps a pruned node can get somewhere in the area of sub-10G, but a "full node" is actually at around 328G: https://www.statista.com/statistics/647523/worldwide-bitcoin...
"Full nodes download every block and transaction and check them against Bitcoin's consensus rules." (https://en.bitcoin.it/wiki/Full_node#Archival_Nodes)
Pruned nodes do just that.
The blockchain data structure means that once verified, you don't need to store old blocks. You only need the most recent blocks to verify new ones.
The nodes you're talking about, that store the entire blockchain, is called an archival node.
Anyway, encouraging people to install full nodes, pruned or not– which enforces the rules– improves Bitcoin's decentralization.[0]
[0]: https://bitcoin.org/en/bitcoin-core/features/validation
At best it's a gateway drug to get people more involved.
Interestingly, running a lightning routing node actually is a way an individual can run a full node to not only generate some fees to cover the cost, but actively and consistently participate in the cyber economy and have a marginal voice in enforcing the rules. The nodes you have channels with are incentivized to care about your vote if they want to stay connected to you.