I only used spinning gear for a lot of years, because that was all I had. Once I went to baitcasters, I added several, but I also fished for other fish besides bass.
If you stick with spinning gear, I found that one rod won't do everything well, which was another reason I decided to give the casting gear a try. I figured if I was going to add more rods, they should be geared towards specific techniques, and spinning gear often is not.
I have a several spinning outfits too now, and they're still a part of my fishing, so if it works for you, then no real need to go to baitcasters. Both are good to have & use, but not for everyone. I'm not a tournament anglers, so learning to use them both was just for my own personal satisfaction & enjoyment.
You could give fly fishing a try! Now there's something that also takes some time to learn to do properly and you might be giving baitcasters a second thought!