Although floating gravity block generated in natural but have you ever asked: "Can you make floating gravity block in 1.17.1 ?" That's right! Yes! Here is how:

Step 1: Place a command block

Step 2: Set the command:

/kill @e[type=falling_block]

Type: repeating; unconditional; needs redstone

Step 3: Place a lever near the command block and flick the lever to turn on the command block

And you are done, every single gravity block is floating even you update it

If you don't like to be bothered by the output of the command block just press "/" and write the command:

/gamerule commandBlockOutput false

If you want the gravity block fall just flick the lever and update the gravity block and you are done

This is work on almost every version in JE and even BE