To be clear, Elementor is not the only pagebuilder that grew users in 2020. The article linked at the top singles out Elementor for its “exponential growth” but it says that 2 other pagebuilders grew this year: BoldGrid and PageLayer.

Sincere question (I’ve never used or even tested a pagebuilder in 12 years with WP):
Can it be that any decline in other pagebuilders may be due to leaving WordPress for another solution? Is it known that the people abandoning pagebuilders are choosing Gutenberg over another non-WP solution?