Are you sharpening at all in post? I went about a full year wondering why my shots weren't sharp at all until I realized my default settings were with no sharpening at all.
Also spent a few months with noise reduction turned on with my Canon 6D which was softening all my photos to reduce noise. Turned that off and it changed everything.
If you want to email me one of your RAW files, I'll play with it a bit and see what I can come up with, and email you back the PSD file with the layers. The kit lenses these days are much better than 5 years ago and will still take amazing photos, but some new glass will blow you away.
mdaveyphoto@gmail.com