Just because I'm not afraid to sound like a dumbass,
Does Bitcoin have the ability to actually replace all of those transactions that are currently done with fiat & digital money?
Or will there be something else that comes along & Bitcoin was really like the Model T that kicked it all off and made it mainstream?
That is the million dollar question. Likely something will replace them yes. Whether it is Bitcoin or something else remains to be seen. Bitcoin enthusiasts like to say that whatever Bitcoin can't do currently will eventually be forked into doing later. Others think something will eventually replace it.