Just happened with me here. It would boot, but not display any image, or initialize the display incorrectly (576p?). Saw someone online saying they had fixed it by disconnecting the HDMI, booting the PS4, and then connecting the HDMI and turning on the TV. Tried that and… it worked. No idea what happened or why.
Anyway, I might look to buy another PS4, or maybe even a PS5. When the PS4 was not working my kid was heartbroken (he loves playing games on the PS4, even more so in the weekends) and I’d rather not see him like that if I can prevent it. ;)