Any methods or tech to reduce the size of blockchain?
In cases like VPS it seems that the storage on plans rarely increases much despite HDD size increasing nearly ten-fold since the beginning of 2009.

Depending on how you use the node there are several options to reduce storage requirements. Here are a few:


Enable pruned mode on the node.
Use an SPV client like Electrum in place of Bitcoin Core.
Enable inline file compression (if available) i.e. btrfs compression.