>In my opinion Sprint right now is where T-Mobile was 5 years ago.
I send >30K SMS per day to the continental US and a large percentage of those receive replies. With the replies, I get carrier info.
For the entire US last week,
'Verizon','0.48'
'AT&T','0.31'
'T-Mobile','0.10'
'Sprint','0.09'
'Other','0.02'
For the entire US one week starting 5 years ago
'Verizon','0.46'
'AT&T','0.33'
'Sprint','0.08'
'Other','0.07'
'T-Mobile','0.06'
T-Mobile hasn't hurt Sprint. Sprint is basically in the same spot it was 5 years ago. AT&T and Verizon are also largely unchanged. The only action is in T-Mo eating up subscribers from the small carriers like cricket and metropcs.
T-Mo has eliminated all the smaller competition. The US gov did not create/preserve competition by blocking a Sprint+T-Mobile merger. Neither Sprint nor T-Mo alone are mounting a serious challenge to the big two.