Running a full node is one of the most underrated activities you can do in Bitcoin. Here are a few analogies that may help you understand why it is important.

If you transact in Bitcoin and don't use your own full node, it's like buying gold from a random gold dealer and simply taking them at their word; that what you bought was actually gold and not something else without verification.

Imagine if someone were to pay you via bank transfer and you got an SMS alert from what may seem to be your bank; only for you to get to your bank and be told that the transaction never occurred. Alas, you were sent a fake bank transfer alert.

Every Bitcoin user is self-sovereign and there's no authority to go to for restitution if you've been aggrieved. The way to protect your self-sovereignty is to use a full node when transacting.

You may not have to run a full node by yourself. Sharing one with family or friends is sufficient. What is important is that you are doing your own validation of the blockchain and the individual transactions.

Without self validation, your Bitcoin is just another hosted database with API endpoints to check balances. Running a full node does not protect the network, it protects you.