The company decided to make radical changes to its business model.

Relating to or affecting the fundamental nature of something; extreme or thorough.
They proposed radical new ideas.
His views were considered radical.
We need radical solutions now.
radical change
radical reform
radical approach
extreme
fundamental
thorough
The activist was considered a radical for demanding immediate societal reform.

a person who advocates for fundamental or extreme changes in political, social, or economic systems
She is a radical thinker.
The group included several radicals.
He was seen as a radical.
a political radical
a social radical
the radical fringe
revolutionary
dissenter
extremist