The short answer to this question is probably yes. You can improve your editing skills with a graphic tablet, and not just because you swapped your mouse for a shiny new toy. Working with tablet at least for me is much more enjoyable experience. It feels more natural to use a pen, then to click around with my mouse.
For the last 18 years I have been using mouse for image editing. But lately I started having problems with my hands, mostly a bit of numbness and weakness in my right hand, especially when editing a large batch of images. A friend of mine suggested me to get a graphic tablet, he said it worked wonders for him. And recently I bought a new Wacom One medium size tablet, and fell in love with using my computer once again. Now I use it all the time, even for browsing the web.
When used in graphic applications it gives you another dimension, you can regulate the opacity or size of your brush simply by applying more or less pressure. Combined with natural hand movement it makes editing a joy. Making mask selections is much more enjoyable experience when using your tablet, no more clicking, you just need to tap the board. This alone makes a great difference, before I had up to 5000 clicks with left mouse button on a single image. The last time I checked the Mousotron it was around 3.000.000 clicks for the last two years, and that is only for a lmb.
Graphic tablets come in various sizes and options, from simple ones with only draw function to advanced models with touch function, built-in screens, custom buttons and all the bells and whistles. One of the main differences between them is active tablet area size. Low end models have usually 152 x 95 mm (6.0 x 3.7 in) active area and 1024 pressure levels. This is fine for most applications but artists will want a bit more free space to let their creative side come alive.
I recommend getting a Wacom tablet. Their product range is great, from really cheap to expensive professional models.
One thing to have in mind is that not everyone will swap their mouse for a tablet, it is a personal preference. If you can, borrow it from a friend for a couple of days to see is it the right tool for you.