I always sort of thought that calling yourself a CEO or managing director of a small company sounded pretty lame and pretentious, but that founder worked quite well as a modest but accurate job title.
I don't know if that was ever true or if it was only true in my head but either way I think that the term founder has picked up some baggage in the last decade.
There can be big marketing wins in associating yourself closely with your brand.
It's a big risk you take, and you must be confident enough in yourself to take it, because it can be soul crushing if your startup tips over.