So the reason is that no-one can afford to out bid them.
I think that would better be described as "market cap", which is certainly a much bigger number than "cash on hand." The latter is basically liquid assets, which I think is a much more important metric when we're talking about outbidding competitors for fab space (among other things).
> "Cash on hand can be defined as cash deposits at financial institutions that can immediately be withdrawn at any time, and investments maturing in one year or less that are highly liquid and therefore regarded as cash equivalents and reported with or near cash line items"
Source: https://www.macrotrends.net/stocks/charts/AAPL/apple/cash-on...
Apple's net income has been at least $20bn every quarter for the past two years[1]. Both Intel and AMD make a small fraction of that[2][3].
[1] https://www.macrotrends.net/stocks/charts/AAPL/apple/net-inc...
[2] https://www.macrotrends.net/stocks/charts/INTC/intel/net-inc...
[3] https://www.macrotrends.net/stocks/charts/AMD/amd/net-income
Intel has their own foundry, AMD is quite happy with whats a fairly recent move to 5 nm. Graphics card manufacturers are more concerned with selling off old cards than making new ones.
Apple isn't going to get very good yields out of 3nm and will likely only get to put it in a few products for now, but for a few months they get to say they'll be the biggest baddest company on the block, which is what apple marketing is all about.
Qualcomm gets the entire mobile market either way, and for desktop/server manufacturers apple isn't an option. Apple 3nm doesn't directly compete with amd/intel, so why worry
At the same time, chip shipments have dropped like a rock as everyone braces for recession. Nvidia allegedly even tried to cancel most of their N5 orders because they didn't think they could move the chips.
Apple is pretty much the only company willing to pay large amounts into a risky market. There may not have even been any serious bids aside from their own.