if you never practice your handwriting with the intention of improving the quality of it then nothing will change.
i always had very neat handwriting, to the point where other classmates would call it girly because of how "pretty" it was (i would sharpen my pencil then wear half of it's cone down to being flat and write with the edge of the flat part to get a calligraphic print), but i also wrote quite a bit. when i was 3 my mother would have me write the alphabet twice, uppercase and lower, and then once in cursive. i stopped writing in cursive in the 4th grade only to want to learn how to do it again in my twenties, so i started practicing each letter just like the alphabet and it initially looked like shit. it was legible in that you could make out the words but sloppy all the same. i made a conscious effort to correct each letter until my hand and wrist grew comfortable and familiar with shaping them. it took roughly 2-3 months for my cursive to start looking consistently good and another few years to be able to change to different styles of cursive and still have it look nice.
now funnily enough, because i spent so much time writing in cursive for a stint, my regular old printing handwriting suffered for it because i was no longer making the same hand and wrist motions, not to mention that i had also only been writing in pen, not pencil, so there was no edge to wear down. i then compromised with myself and just bought a couple of calligraphy pens, which can print and do cursive equally well.
but yeah, practice writing the alphabet if you want it to be better. eventually you'll like the shape of one of your letters and you'll try to get it again and again and again when writing. it'll get gradually easier and you'll end up writing them as naturally then as what you posted now.
