Do you think bike frame size is less important these days?

It may seem like a silly question, and i know bike companies are all making those shitty compact frames

Compact frames are not shitty.
They allow people like me (5'7" with 30" inseam) to safely stand over a bike that fits them with regards to effective top tube.

but it seems that the advent of mass produced bikes has allowed longer seatposts and stems that allow for more frame sizes to fit more people.

It may seem like this, but it has'nt.

I am 6'2 and a bit, and ride two bikes, one i built which is 53cm c-t and a fuji track which is 61cm not sure if its c-c or c-t, but i find the fuji considerably more uncomfortable in almost everyway, bar the fact the smaller frame has a slight toe overlap problem. What do you think?

I currently ride a 51cm track frame (51cm ETT) with a 110mm stem; and
a 52cm cyclocross frame (54,5cm ETT) with a 80mm (effective length) stem.

My ideal stem length would be ~100mm, but even with these two similar sized bikes I've had to compensate alot with stem length.

I could'nt imagine riding bikes with a 7cm difference.