This is a strange answer, it turns out that I pay money for this, I don't get anything, and is this normal in your opinion?
If there is no way to improve sound quality, then you need to add capabilities with the integration of room acoustics, for example...
First of all, the people you are talking to in this thread, myself included, are users just like you. They don't work for JRiver and it's not their job to improve the software. We all paid money for it, just like you.
It's perfectly reasonable for you to expect improvements in the software to induce you to upgrade. MC27 actually hasn't yet added anything I really consider important either.
But you asked specifically about sound quality (or "SQ Sound" whatever that is). And the answers you received were quite correct. The sound quality from MC is already bit-perfect. It's as good as it can be, and as good or better than any other software. So what improvement on perfect is there? Anyone who thinks "perfect" can be improved upon is confused.
The way to increase the sound quality you experience, once you are using MC as your source, is to improve your reproduction equipment (like speakers or headphones) or listening environment.
There are other types of sound related improvements, related to processing, one might request, like I want a different filtering algorithm, or I want an enhanced spatial processing algorithm, or I want a 50-band graphic equalizer. But these are sound manipulation (DSP), not playback quality. The VST3 effort is in this category.
But there are several other threads talking about the other feature-related improvements being made in MC27, and those that are planned. You might want to check out those threads, read about the new features that have been introduced, and ask questions about those. There are threads specifically about Tidal and Qobuz, did you know that? You can also make feature requests on the forum and JRiver staff will see them and might implement them. But if you request an improvement in sound quality, expect to be asked "How, exactly?"
It's naturally up to you to decide whether to upgrade or not. Your fellow users have no interest in persuading you one way or another, so you shouldn't be surprised if they fail to make what you consider persuasive arguments.
Good luck, and happy listening.