As we humans age, our hands get less steady. Just the slightest tremor can make a photo just slightly out of focus.
Also how you press the shutter matters. It is like the trigger to a rifle. They don’t say “squeeze one off” without reason.
If your photos aren’t as sharp as you would like, watch how you release the shutter. Squeeze, don’t press or poke.
And if your hands have the slightest tremor, get some kind of support to steady your camera.
The pros, especially as they age (and become more experienced) often use tripods and external shutter releases even in the studio.
All the great bodies and lenses you buy won’t make a difference if the camera isn’t rock steady when you take the shot. Especially on a long lens when you are zoomed in.
I’m saving my money for a Peak Design Travel Tripod. Probably the best tripod ever made. $600 for the carbon fiber model. Weighs next to nothing and fits in a water bottle compartment of a back pack.
Not cheap, but has a lifetime warranty and every single part is user replaceable. This is the one you buy for life and take everywhere. Sets up in less than ten seconds. Can a actually set up just inches off the ground.
I have no connection to this company nor do I earn one penny from this endorsement.
I just think it is a great product. And regret I didn’t help fund it on Kickstarter a few years ago as I now wouldn’t need to save so much money.