I find the boutique stuff to sound substantially better than the best muffs... everything thats good about the best examples with a lwoer noise floor and very carefully refined voicing or lots of controls to refine it for yourself. i still don't like the muff much, but my skreddy and stomp underfoot stomped allover all the muffs I owned prior.
Oh they absolutely will! Cannot even pretend to defend on that. The Boutiques will do that and so much more.. build quality and care, selection of components and a decent handful of other considerations thrown in.
I think where I was headed with that blanket statement, was that if someone was SPECIFICALLY after that old Big Muff sound, and did not feel they needed to drift too far from it, then they should grab an old Big Muff or something that does JUST THAT... so that they can know for sure.
Stretching that analogy a bit to take everyone out of the blanket of distotion/ fuzz/ od/ dirt which gets a bit blurred at best of times...I would look at this comparison:
This kinda follows that same principle of someone buying an expensive boutique phase or flange pedal, so they can dial it down to emulate chorus voicings that they heard on a song or an album and liked. While they bought it to reach that desired mark, they will invariably stray from that with every other option present... defeating the initial exercise of wanting that chorus sound to start with... because there are many options present.
So going back to the Big Muff, maybe the OP wants to be able to dial in a sound but also wants the versatility to branch out... then yeah! boutiques open a thousand doors. But to find out if the Big Muff is the sound for you.... start with a Big Muff. Not a double or a Metal or a tone wicker... all trying to compensate for the original circuit. Keep it simple and see how you work with it, and it works for you.