FWIW, starting a sentence with "Honestly ..." always makes me think the rest of what this person has to say is dishonest.

Your BIO on HN is:

> I HAVEN'T SHOWERED AT ALL! THAT'S WHY I REEK! WORKING IN FINTECH! AIN'T SHAVED IN WEEKS! POUR CRUMBS FROM MY KEYBOARD! THAT'S WHAT I EAT! WROTE A CURRENCY LIBRARY! 3RD TIME THIS WEEK! LURKING HN! I PREFER /b/! IN MOM'S BASEMENT! I'M THIRTY THREE! IT'S 3'O'CLOCK AM! THAT'S WHEN I SLEEP! AH!!!! COME ON FUCK A GUY!!!!

What level of credibility are you seeking?

So a sentence starting with "frankly" means they aren't a frankfurter?

Ngl I think that bio is hilarious.

"Honestly" is a colloquialism used to indicate disbelief with the previous statement or to preface candidness. Choosing to interpret the colloquial use of "honestly" as an indication that everything else that person says is dishonest is a very weird trait I've only seen show up in grammarian literalists and pedants that only makes yourself seem like a disingenuous person.