TGX will come back soon to the race. There is a single Dev and he was busy in some of his personal things. And TDLib was also lagging.
Next version of TDLib is going to support many missing features and eventually it will come to tgx too. It will be worth for the wait. I am sure Dev is not going to disappoint us.

I have not compared or read the code, but in my experience if that was the exact case of copying code, TGX could have also brought below features without any issues and could have released a fully featured statistics.
1) Zoom out for languages
2) Pie graph for languages
3) Recent posts statistics
4) Checkboxes

And there were bugs in TGX which is not there in Android classic client, and Overview section was available in TGX before the legacy client implemented it

I have a little announcement: sorry for a big update delay. Update with animated stickers and new features for groups is almost ready and should get to public beta next week.

Please keep in mind that many feature that TGX lacks compared to other clients require TDLib, on which it is based. First I need to wait until it gets them, then I'll be able to start working on them. Also the way server API works is that you can't simply implement more important X without implementing all little stuff that was released before X.

Example: I received fully working animated stickers API support just this week and have to 1. Implement them everywhere needed ASAP. 2. Test it. 3. Since other clients already have them, I have to make them work better than in any other client, which had a chance to make experiments for weeks.

In about mid-August, when TDLib should receive full support for some essential missing features, I will return for an update streak many of you miss and message me about.

TDLR: No, TGX for Android is not discontinued and update streak soon will be recovered.

He did it, but it couldn't show animated packs

But animated stickers playback is already implemented