What exactly happens when the Main flash memory (User application code) is selected as the boot area?

I've gone through the STM32 boot process

https://community.st.com/s/article/faq-stm32-boot-process

After the boot mode configuration is resolved by means of the BOOT0/BOOT1 pins or the nBOOT0/nBOOT1 (from the option bytes); the controller chooses the specific boot area. So suppose if we chose the Main flash memory as the boot area (0x08000000), then will the controller directly jump to the user application or will it first jump to the boot loader, initialize the necessary configurations (in case there are any) and then jump to the user application? It seems that STM32 doesn't perform any firmware integrity test before it runs the application so there's no need to jump to the boot loader right? But if it does, then why?