This is exactly that - a guess.

As long as there is no "economical" value proven AND money on the table, there will be NO MINE (like in 99% of exploration projects) and no buyer.

If ZEN.V would be a 100% sure thing it would have been taken over already!

Apparently potential buyers are not in a hurry at all.

Also why were there no bigger strategic investments so far? (in the 10-20% range) from potential future buyers?

Tell me why at a market cap of only $38M no buyer is stepping in - offering a cool 50% to current stock price (<$60M) and taking out ZEN.V?

Let me tell you why - Because there is still a lot to be proven, developed and a ton of money to be invested in order to maybe one day get a product someone is willing to take off.