In 2018, Belgium passed a new law that concerns in particular services provided via an approved collaborative economy platform. This law came into force on August 5, 2018. Deliveroo is part of the approved platforms for Collaborative Economy and the people who provide services in the collaborative economy are called "P2P". This law allows P2P riders who are part of this type of economy to earn a certain amount with low taxes. In 2022, this amount is 6540 euros.
Here is a useful link (French - Dutch) about the collaborative economy.
Here is what is taken into account by the collaborative economy regime: