I suspect a simple reason 'they' can't buy all the shares is...

I suspect a simple reason 'they' can't buy all the shares is because some people would not sell them. Even PH holds only 5%

	Name	Equities	%	Valuation
1	Paul Hopper	422,219,760	5.889%	28 M $
2	Mann Family	291,281,412	4.063%	19 M $
3	The Vanguard Group, Inc.	244,288,515	3.408%	16 M $
4	Nicholas Smith	118,000,000	1.646%	8 M $
5	Vanguard Investments Australia Ltd.	109,783,697	1.531%	7 M $
6	Norges Bank Investment Management	82,036,374	1.144%	5 M $
7	Leslie Chong	79,916,666	1.115%	5 M $
8	Mi Ok Chong	77,000,000	1.074%	5 M $
9	Netwealth Investments Ltd.	60,576,704	0.8450%	4 M $
10	Sve Capital Pty Ltd.	23,000,000	0.3208%	2 M $

ref: https://www.marketscreener.com/quote/stock/IMUGENE-LIMITED-10353137/company/

So the price would go up dramatically as they started to buy in. If they made a bid instead, it wouldn't take long for an alternative offer to come in I would think.