The command "Do not love the world" is strange coming from John, who wrote the words "For God so loved the world"!
But here he is not talking about God's heavenly love for His children, His creation. John is talking about love for the material things of the world. Again, this can be confusing; John isn't saying we cannot enjoy the nice things in our world - he is condemning the greed, envy, lust, and others that lurk beneath the surface of chasing worldly pleasures. Any desire or pleasure can become the pride of our life, and take the place of God.
John says that love for the world is incompatible with loving God. The human heart is designed to have one thing at it's forefront. If God is in that place, then nothing else will be important to us. But if the world and things in it are there, then there will be no God in our life.
Nothing in our world lasts. This is a fundamental truth of the world. So to set your heart on the world is asking for it to be broken. Nothing will last and you will be forever chasing the world in futility.
COVID-19 has been a time where those things we love and chase may have been taken away. God is saying "so what do you really love?". This can be a time when we connect with God, put Him in His rightful place in our heart and start to chase and follow His way, not the world's. We have been designed by God to love God. There is a better way to live than to run the futile race for worldly pleasures. There is a life that follows God, and strives to live for His kingdom.