To say that the modular synthesizer is back is an error, because it never went away...
The seductive sounds of the new (and also old) range of modular synthesizers are probably too intimidating and sonically complex for the "normal" musician (the one that uses presets rather than sound construction).
When I say that the modular synthesis never left, it's because since its creation and development (1940 to 1960) it has remained active in personal laboratories, in classrooms and in the experiments of composers, insatiable seekers of new sounds, rhythm and noises.
For most people, a synthesizer is a keyboard with a panel populated by LEDs, buttons and knobs. A look of disbelief arises when they are shown a modular. What is this? Why so many cables connected? Is it an old telephone switchboard? It's not a synthesizer!
The irony is that the modular ones were the first synthesizers, the only commercial synthesizers until the arrival of portable models already wired internally, such as the Minimoog.
Most commercial synthesizers today are digital: their internal computers emulate the various forms of analog synthesis. The same happens with a laptop loaded with VST plugins running some DAW software and provided with a quality sound card.
Then we have the analog non-modular synthesizers, Moog, Alesis Andromeda, the most recent Prophet 12, Roland, Korg, among others.
And in the most esoteric and niche area we have the modular, where unlike a non-modular, you can decide the configuration of your monster according to your own tastes: filters, oscillators, mixers, ring modulators, sequencers, effects, very rare sources of effects, random, sampler, etc. This flexibility is very different from non-modular systems and the possibilities become endless. A modular synthesizer can be what you want it to be - if money and space allow it - do you want three oscillators? Six? 15? Two filters? One Multimode filter? Two Lowpass and three Highpass? How about a vocoder or a theremin? Maybe you want a specific filter from a Russian synthesizer of the 60s? Most likely, someone somewhere in the world will have built a module that will satisfy your desires. In other words, the module-to-module configuration never ends. You will always have the possibility of adding a new filter, a different oscillator or very particular modules that simply do not exist in the world of non-modular analogues.
Modular synthesizers are instruments that are not fixed, their owners are continuously adding modules that even allow them to change the scope and focus of their system according to their tastes and current objectives.
It may sound like hyperbole of traditional advertising, but the world of modular synthesis is actually only limited by your imagination.