If you have a significant market share in Australia then you...

If you have a significant market share in Australia then you will only achieve a topline growth inline with population growth if you stick to your original market.
Even companies like Coles & Woolies have moved into different markets to achieve higher growth e.g insurance, white goods etc.

There are very few growth companies in Australia that haven't expanded into different markets either geographically, through different product lines domestically or both.

I own sixty-odd stocks.
My 20 biggest holdings - ARB, AUB, BRG, CAR, CSL, DDR DTL, EZL, FID, LYL, NCK, REA, REH, RMD, SDF, SHL, SNL, TNE, WHC - are in the same businesses today as they were a decade ago.

All highly successful businesses.
Not one of them was at one stage fowl, which then became fish.

As for your example of Coles and WOW, they have not changed their business model by selling insurance, white goods, etc. They are still retailers; i.e., they sell stuff.
All that has happened is that they started selling different stuff, on which they believe they can garner margin. That's just their business. It's what they do that all the time.

They didn't get involved in underwriting insurance or manufacturing white goods themselves, which would have been akin to what APA is doing in terms of doing activity X historically, but then going into activity Y, where X and Y are materially different things.