Why many stitchers hold the cloth
Hand-held work lets you move the fabric around a long needle and smooth the area after each group of stitches. This can be helpful when the design uses long straight runs or more than one layer.
It also means the fabric can remain relaxed rather than being held drum-tight. That matters when thread tension is already causing puckering.
When a hoop can be useful
A hoop may help if the cloth is very light, the design is small or you find it easier to keep the marked area visible with gentle support. Use only enough tension to steady the cloth.
Remove or loosen the hoop when you pause for a long time, especially if the fabric is delicate or likely to show a ring.
Choose the method that protects the cloth
Test the same short row by hand and with light hoop support. Notice whether the needle passes cleanly, whether the cloth puckers and whether your grip becomes tense.
A hoop is a tool, not a requirement. If the fabric moves naturally in your hands and the stitches lie flat, there is no need to add one just because another embroidery method uses it.