Depends on the company. I've been working for marketing agencies for the last 15 years and they're generally staffed by, at most, 1 IT person who is in charge of a third-party vendor relationship that offers managed IT services. Those IT resources (internal or vendor) don't specialize in data and often don't know how to deal with it well, predictable workloads or not, and often offer up solutions which are not appropriate (cost or otherwise) whereas there are managed solutions from cloud vendors that do. BigQuery, for example, handles compute and storage for you and rolls it into one reasonable query price. No need to worry about any management of anything there and just sit Data Studio (included) or any other BI tool (Tableau, etc) on top and you're good to go.
I get your skepticism and welcome it, but you're being a little rough. We're cloud native at my current company (I did a partial cloud migration at my last which was completed after I left) and it makes my life leading a Data Engineering and Data Science team MUCH easier without upfront hardware/software costs or long-term contracts, which were STAGGERING and left us with much more difficult to maintain, upgrade, etc hardware that took up most of my job as opposed to almost none of it today.
YMMV.