[humbledrone]

Speaking for myself, the accessibility and convenience is a huge part. Instead of lugging around a 60 pound fragile finnicky pedalboard, I just throw my Helix in a backpack and am good to go. It has way more pedals in it than I could fit on a real pedal board, and I can also switch presets with the tap of my foot (including rewiring all the connections between pedals, changing their order, swapping pedals, swapping amps, etc).

And yeah the sonic possibilities are endless. On a physical pedalboard, it's pretty involved to rewire everything to change the routing, or add/remove pedals, etc. With the digital modeling ones, this all becomes trivial and you can try all kinds of different setups much more quickly, save them and go back later, share them with friends, etc.

All that said, it's kind of like asking an acoustic guitarist in the 1950s why they would use an electric guitar. Electric guitars obviously have lots of advantages, but it's not like people stopped playing acoustic guitars. I still think real analog pedals are cool, they're fun to collect, in some cases they sound better, etc. And sometimes you don't need the mega-flexibility -- if you have a 4-pedal setup that does "your tone" maybe that's all you ever need.

[duosonic]

I think those are perfectly valid reasons for going with emulation.