There is a difference between the el-cheapo tuning pegs on a cheap guitar and those on a quality built guitar.

Replacing them will very likely make a noticeable difference. They tend to be smoother and hold tension a bit more securely. The internal tolerances and overall quality of the parts make that difference.

If you have a "cheap" guitar..... and replace the pegs for $50, that's probably going to be a good deal and you should see an improvement.

The bigger issue is, do you stop with just the pegs or do you continue to upgrade the other parts to match? Bridge, pickups, controls, etc.... Remember that under the accessories, there still exists a cheap guitar. There's a huge world of difference between the USA Fenders and the Chinese knockoffs. Money spent on accessories will likely never be recovered in a sale.

But... if it's a good guitar and you like it, and want to keep it.... upgrade it.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.