Is it necessary to buy a 4K camera now?

I don't think it is necessary for ordinary users. A truly usable 4K camera is very expensive. For a camera within 20,000, that 4K is basically useless, because the frame rate is too low, only 25 frames/second or 29.97 frames/second, and the photos taken are so shaky that they are not used at all. 4K is useful only when it reaches 50 frames/second or higher. If this frame rate can be achieved, the cameras are all over 30,000, and the memory card is also very expensive. I wonder how many cameras with such a high price are acceptable. Don't think that 4K marked on the chassis is a 4K camera, and it is not a real 4K camera if it doesn't reach 50P.