The Digitakt is a great first device. It will introduce you to the Elektron workflow very nicely, give you a plethora of sound choices as well as sound modulation/modification, and it is a very expandable system. The high power midi control capabilities allow you to grow your system and still keep the Digitakt in your workflow. Its not so much about future proofing for me as it is investing in a solid studio piece that will get lots of use!
I think you will find that something with the flexibility of Digitakt will really open up your creativity and inspire you to try new things! I have many synths/drum machines, a lot of them collect dust, but since I’ve got my Digitakt I always find it in my projects.