Each raw processor has a different default starting point. A good comparison is where you eliminate as many variables as possible so that you may focus on the one thing you would like to examine. It matters what is happening in the mid tones and shadows because processing the rest of the image would likely affect the overall composition of the image including the highlights, unless you are doing a lot of masking and local manipulation.
In other words, if your starting point is already heavily processed like ACR, then pushing the highlights any further along the slider would yield unnatural results, even though the developers have included a scale with a wider than useful range. At the opposite end of the spectrum, if you start with RawTherapee’s neutral profile, this means barely anything is acting upon the image and thus you have more leeway to achieve your objectives.
The thing about dt and RT is that they are very if not more powerful than commercial software because of the number of advanced tools that you have at your disposal. They aren’t workarounds, but you need to spend more time learning to use multiple tools to achieve what you want. Fortunately, when you get there, you are on top of Mount Everest instead of base camp.
That is why many people use dt, RT and the other fine apps we talk about here. Not just because of FLOSS philosophy but because they work well.