Ann: South Erregulla Peaking Power Plant, page-228

Reasoning you'll probably find same as Stuart has said cheapest gas (cost around $1GJ )
Cheaper extraction, close to major consumers (reduced transmission costs) which equates to cheaper energy costs.
Cheap energy costs for government means jobs , manufacturing competitiveness.(basically a strong economy)
Beach's exception was due to exceptional circumstances/covid era . Short window to do so and can't see it now being repeated . Think you'll see some major changes to offshore seems they've been tweaking numbers and avoiding commitments .
Only big but/if is if government allowed offshore to supply their commitments from another field onshore then their "could " be some massive M/A action