I'm curious as to what other people think, about that the latest feats that has been added, have "Prerequisite". 

I know some feats in the past, was also like this. But back then feat and stat increase was 2 different things (thought you only got 1 point each time). But the difference is, you could point the stat point where you wanted to. Those that inscrease stat, often lets it be 1 of 2/3 different stats. And if the feat involves a DC, then the stat increase is what the DC will use. Plus in the past, some feats might just have been more impactful. F.x there was a feat that gave +2 damage with a specific weapon. More martial classes had more attacks, plus you had as many attacks with you off hand weapon, as your main hand, if you duel wielded. There weapons also had different crit chance and crit multiplier. Ranged from crits on 20 to 18-20, and the crit multiplier was 2-4x damage. And everything got multiplied. Plus there was a feat that would increase the crit chance. Just to name a couple of feats with requirements. People that played 3.0 or 3.5 knows about these things. Or played Neverwinter nights 1 and/or 2

They’re overhauling feats in the 1D&D update. Note that the recent level 4 feats all give a +1 ASI as well.

But you are limited with which stat to increase. As stat, those that involve a DC, that stat increased, will affect the DC. So it would be prefered to increase the main stat with them

All the ones in Planescape are “increase any stat by 1” and only 1 uses a DC. Bigby’s gives a set of three options for the +1, and the DC itself is based on which stat you increase, so you’re hardly going to be locked into having a low DC or taking a stat you won’t use.

I haven't seen the planescape yet. 
But the DC might not be that great. It could be to even out a stat. The barbarian in my group needs to even out his con 15->16. We are level 6, close to 7. With these feats, it wouldn't be until level 12, before he could do that. That would be a DC of 15 i think, for the bigby's. I'm not sure that is that good at level 

Shrug. I don't know what to tell you in the present. Regarding the concept as a whole, I'd call it a matter of planning out your stats with what feats you want in mind. As for the DC, it's not bad. Only full casters need to emphasize getting the absolute max DC possible.

That is what i try to do. But it's hard when the stuff gets released, or even announced after you have already done something

It happens that there will be times that either due to planning or new releases that you might want a feat that doesn’t give the stat bonus you want.

It happened to me with my Druid. Got high enough (level 12 ASI) that I wanted to take Fey Touched. A bonus to Wis would have been nice but I already had it to 20 so I ended up putting it in INT (we rolled stats and with a 4 CHA bumping it to 5 wouldn’t have helped) which is now 11. Fey touched wasn’t out, that I remember, when I made the character so focused on getting WIS to 20.

Sometimes you have to make choices and decide if the feat is still worth it with the wrong stat/DC increased or is it better to take the ASI.

4e did this in spades as well. I always enjoyed feat trees because the later feats could be better than an entry-level feat and you could feel like a real specialist. It is more of a challenge in current 5e though due to the slow pace of feat acquisition.