I'm Ben. I've been doing this since 2020, and the content I've made for clients has passed 500 million views (and I last counted years ago).
Channels I've grown have earned 5 silver play buttons (100k subs) and 2 gold ones (1M subs). I've taken plenty of accounts from nothing to hundreds of thousands of followers, and two of the businesses I work with are seven and eight figure companies that are still growing because of the content.
I've worked with established businesses and start-ups. One start-up I helped build an audience, then he launched his first product and made £100,000 on the first launch.
The method behind all of it hasn't changed: it's not about you, it's about the person watching. Work out what they actually want before you make anything, and the views and the customers follow.