I just read this whole thread, and I think it completely misses the point of what's really necessary, to be honest. The entire college landscape is changing rapidly. The "arms race" of facilities is going to be coming to a close, in my opinion. Now, does that mean we shouldn't look at Williams Arena for the purposes of making things better for the fan experience? Absolutely not. However, if we're talking $200 million+ to improve the program, I'd far prefer we find ways to get that into NIL funding than in facility improvement. Otherwise, we're going to have a new arena with the fanciest cupholders in town, and a 13th place team playing in it.
With that said, if something were to be done, I've always said that there is room to add an atrium (think Lambeau Field) to the southeast corner of the building. This could be a multi-level addition that could create either direct access or a walkway (on the North side) to two-level level concessions and restrooms, as well as breathing room to walk and elevator access. The only area that would have smaller walkways would be the north side, but relief to the rest of the building would create less walkway space. I'm no architect, but I've included a screenshot of the space it could add, which is quite large, without hardly touching the actual arena. This also opens up opportunities to add ADA seating to the upper levels on the South and East seating areas.
I've been to Hinkle Fieldhouse, and I've been to Cameron Indoor Stadium. Anyone who thinks teams can't win in old facilities is fooling themselves. The concourses at Duke are about 2/3 the width of the Barn, and you sit in a wooden chair. Hinkle is renovated, but it's still exposed brick in the concourses, and there's not really all that much extra space under the seating. With that said, the Barn does need some improvements, and I think they can be done, but an arena is not going to be the ultimate solution, be it new or renovated.
I think we're trying to solve a problem when a much bigger one is out there. The era of NIL is clearly upon us. The money needs to go there.