Such sentences display such a weird understanding of how the federal government works. How can the administration “tighten its hold” over discretionary grants? These aren’t Congressional appropriations earmarked for specific projects. The administration is the only entity that can exercise control over these grants. It would actually be a huge problem if the administration didn’t have a tight hold on these funds. That would mean grants would be going out without close supervision by any elected officials (Congress or the President).
Given the large number of grants that go out, and the relatively small number of elected congress people and presidents to supervise them, and given that their role actually isn't to closely supervise such things, it's not possible to meet a standard where elected individuals are closely supervising grants. As a society, we have decided that the upside of having many grants to maximize the number of opportunities for innovation is more beneficial than having a small number of grants elected individuals can closely supervise. Therefore we have decided to give the work of supervising and allocating grant funding to experts in their fields. This was decided democratically by elected people for a number of reasons.
For one, we have no reliable process to cause good innovations to happen. The best way we know so far is to try very many things and hope that some of them will have very good results. Having a system where we can only fund a small number of projects because we require them to be closely supervised by elected individuals would necessarily mean fewer good innovations (lower ROI).
Another matter is that close supervision by elected people does not guarantee that those funds will not be misused. Instead, what might happen is that small group of people will act in their own self interest, which might be to just become reelected and profit off their position. Researchers' incentives are more strongly aligned to produce good research with federal dollars because their whole careers depend on it. Elected people have no incentive to produce good research, because their careers only depend on being reelected, and reelection does not depend on doing good research, but being popular. A lot of times what's popular does not correlate with what's good research.
Is the system we have perfect? No. But no one has proposed anything better; most of the time what people propose just reinvents the system we have and all its problems (because they don't understand how the system works in the first place), or invents new (worse) problems this system doesn't have.
For the most part, the system that exists today actually reflects that design. The statute and associated regulations for the most part invest authority in "the Director." The Director can rely on committees of experts, etc., but it's more by convention.