Yeah Mahmood, Streeting and Lammy are all part of the same clique and would be much of a (terrible) muchness

Firstly you're ignoring that it's the OPs opinion that Streeting would be worse, they don't say they're speaking for the country.

Secondly your own link shows that of those who know who Streeting is the majority (about 3/4's - 42% of respondents vs 13% of respondents excluding the "never heard of him") think he would be worse or about the same as Starmer. Mind you ALL the rest bar Burnham get a similar response.

Thirdly Streeting is one of the key figures in the clique who drafted the poor decisions that Starmer fronted, it seems a little unrealistic to expect he'd suddenly pivot towards what the people who voted Labour in 2024 actually want if he got the gig. If that's unclear my opinion is with OP - Streeting would be disastrous

The only possible candidate who might win back their support is Burnham, any other choice is shuffling the deck chairs on the Titanic