I do not know the answer to that question, although I have tried very hard to find out. One reason so many different developers exist is probably historical as in the past the influence of developers on films was larger that is the case with modern films.

My experience is that it is better to use one standard developer and get to know it thoroughly than to experiment with a wide range of developers. I have tested most of the developers on the market: Kodak, Ilford, Tetenal, SPUR and other, and found very little relevant difference between them. The standard developers generally give better value for money and are easier to use because more data on e.g. development times for different films and temperatures are available. Your supplier is also less likely to run out of stock with a standard developer than with some odd slow selling brand.

All this said there are differences between developers. D-76 and ID-11 have optimized the grain size/film speed/tonality equation and these are the developers I would always use. However, I now use Kodak Xtol, which has similar characteristics as D-76 and ID-11 for ecological reason. I also use Agfa Rodinal because that is the standard developer that is most different from D-76/ID-11 /Xtol; it has a very crisp grain that can give an almost graphic impact.

For good results it is imperative to determine you personal film speed and development time. How to do this is adequately described elsewhere. It is also necessary to work with a good, no, with an excellent thermometer and a simple digital stop watch. If you use a digital thermometer try to calibrate it against a good mercury thermometer as digital thermometer will give different reading depending on battery status. Low batteries result in high temperature read-outs. Thermometers need not give correct readings, but the errors must always be the same.

I push all film one stop. The advantages of higher film speed clearly outweigh the loss of shadow details which can be kept to a minimum by carefully establishing the optimum film speed and development time combination.