I don't think they simply "gave up the fight".
The FDA imposed hideously expensive regulations and if I was a small to medium business owner I very much doubt I could absorb the compliance costs without at least severe financial difficulties.
Sometimes enough is enough in business and it simply becomes too hard to go forward. (First hand experience

)
I'm extremely sad for their demise as I quickly became a ProVape convert shortly after giving up the stinkies.
I "only" have 3 mods. All Provari's.
And with zero interest in any other brand I'm placing my hope for a relatively trouble free vaping future in these wonderful products.
I wish the owners/directors/staff of ProVape a positive and peaceful future in whatever their endeavours.
Their products continue to play a huge part in my continued health improvements, and for that I'm incredibly grateful