Excuse me Raul, but any system requires a certain amount of gain between cartridge and power amp, or between cartridge and line stage if you have one. The question is how is that gain best achieved? If you don't have a transformer you must have additional voltage gain. Extra components, longer signal path, more wiring, etc. You are spouting the 'simplicity' dogma without considering that your supposedly simpler solution suffers from the same problems in different guises.
There are indeed some very fine, indeed world class, high gain phono stages out there. Aesthetix, Boulder, Manley, etc. Unfortunately implementing them at a high level is difficult. Not many of us can afford to play at that level. If you can, with your 18 tonearm, good for you. Enjoy!
Fortunately there are also some very fine, world class stepups out there. Combining one of those with a top quality MM phono stage (which is MUCH easier to build than an equally quiet and linear high gain stage) is a more than viable option. In the large majority of cases it may even be the superior choice.
The best MC cartridges are very bad at putting out high voltage. Just look at their specs. To hook one up to a voltage-driven gain stage is like asking a car to fly. You may be able to do it, but it will cost you a lot of green. But an MC cartridge is very good at generating current. Voila! Why not load the cartridge to optimize what it's natively good at, then transform the excess current to the voltage we need? Properly implemented this maximizes the performance of the cartridge. Even if there are tradeoffs, the benefits can balance the potential detriments. There are no one-way streets in audio, and pure voltage gain is no exception.
