Am I making a mistake building Superhuman for devs?

I have been cranking out apps for the past few years and loving it.  Then one morning a week or 2 ago I got a little ambitious and decided to build a desktop email client because outlook was so-so and superhuman was ridiculously expensive.  

Is this a big mistake?   Am I wasting my time ?

So far I have Microsoft and Google working and I can do the normal email interaction read, reply, archive etc.   I also got local AI working and training on your emails (all local).

Let me know your thoughts.  

PS: my target audience is developers not the general public