Hi, indeed this is not possible with Monero for various reasons (coinbase verification; can't identify spent TX outputs). In case you don't know, the Mina cryptocurrency has solved this blockchain storage issue. A fixed-size (<30KB) cryptographic proof is enough to validate the entirety of the current state (the latest block).
It requires a network of proof generators with incentives in addition to the block producers. Scalability is not great (similar to BTC) and does not provide anonymity (not a priority either). Checking the state is computationally intensive too (not suitable for smartphones; requires around 10GB of RAM).
It is improving on relatively new cryptography techniques (ZKSnarks), likely to evolve (less stable protocol than BTC; security not battle-tested).