The F4 is a 10+ year old product using a larger geometry. There is likely a larger customer base for these and the F2 parts
The L4 is significantly newer, has some nicer features, and ability to use QSPI external FLASH to hold large amounts of code/data without changing the STM32 IC.
>>To know how other people deal with this shortage, stop their production? or what ?
Plan better, don't expect to be able to make random purchases from retail distributors. The semiconductor business moved to build-to-order decades ago, if ST doesn't have orders/planning info it's not going to know the mix it needs to build. In normal times it takes 12 weeks to make/deliver, shorter times is where they've taken slack production time and speculatively built lines they have confidence that will sell and service random demands from retail distributors.
Yes, when your stock room is empty of the parts you need to build a board you stop production.
You'd understand your costings so you know how much you'd be willing to pay a broker, you'd tell the broker(s) your bid price for specific parts, and you'd watch market conditions.
If the capacity issue gets addressed the price might drop out of the arbitrage market, again watch the market.
Have orders on the books, in normal conditions you might be able to pull in or push out, currently conditions might mean you're limited to non-cancellable/non-returnable orders , and perhaps pre-payment.
If you have an order for delivery next year you might be able to use those parts or sell them on, place the order. Lacking any hedging order you run the risk of still not being able to source parts
