I can't seem to find it, but you had made a mention of where there was a responsive woman, but YOU didn't feel the chemistry.
Well, that's not a fail. It was a decent woman, who had interest in you, who responded, who didn't ghost you, but you didn't feel the spark. So, maybe you will feel the spark with an interested woman soon.
re: replying to emails. I get many many many emails on these sites. I can't respond to all of them. I weed out the ones that say "hi". You need to give me more than a "hi" I honestly don't reply to those who seem incompatible off the bat. Nor do I reply to those who's opening line is "hey sexy". I know that is not what you are doing.
Women unfortunately get tons more emails from men and just can't go through them all. If someone takes the time to write out a nice message, I respond.
One other thing: big turnoff for me is when a guys profile is everything they DON'T want in a woman. When it is more negative than positive. I don't need to know your deal breakers right up front. Reframe it into positives. Again, I have no clue what your profile says, but maybe take another look.
I honestly exchanged a few emails with a guy and then got busy and hadn't logged ont the app (I had actually just been done with it) when I didn't respond, he reached out and I thought it was nice, so I reached back out and apologized and we are reconnected and he is interested in going out, and even though I have put dating on the back burner, I think I am going to take him up on it.
Step back, take a breather. And remember, meetups and hobbies are a good way to meet people too.