I use canva for work, and yes there is nothing wrong with using it.
Canva is useful to design social media posts and basic things like that. However I wouldnt Use their artwork as my branding, not only is it lazy but so many people could use the same artwork, meaning your branding isn’t unique - that’s breaking the golden rule of marketing
They should’ve commissioned someone to design some unique artwork (the illustrations) and then used canva to build their marketing materials around it, like avatars, banners, insta stories etc.
Doesn’t Binky work in marketing?! This is basic, first day stuff!