Sorry for being frank, but the whole concept of dark matter/energy is a complete dead end in my humble opinion. Have you researched about the Plasma/Electric Universe?

You can be frank. There is no problem with this. Everyone has the right to have their preference or opinion. Note however that science is not a matter of preference or opinion. it is a matter of facts: data, predictions, and conclusions.

There is one important point here: data has not excluded the dark matter hypothesis (and the standard model of cosmology in general), whereas it has excluded the electric universe one. There are many flaws in the electric universe setup (please check online, you can find many articles on the topic).

It is not a matter of being mainstream or not mainstream. The idea was interesting, but nature has chosen not to be like this.

Their idea is that all of these concepts were created ad hoc to explain what gravity alone can't explain as it is essentially the only force that cosmologists use. I

The concept of dark matter has been created in an ad hoc way 100 years ago. However, today, there are many independent pieces of evidence that seem to point in the same direction. So this option seems today to be the right one.

In general, as long as a theory/model/idea has not been excluded by data, we must be pragmatic and consider it. That's how science works and progress is made. The rest (i.e. "do I prefer this or that option") is a matter of subjective taste.

What is important at the end of the day is that research is done for all (viable) options, to be sure not to miss anything. Modified gravity, for instance, is still very alive, even if data seems to favour the dark matter hypothesis. Note that on the other hand, data does not exclude modified gravity too. This is the reason why research is made on the two options.