Where to begin.....Why wouldn't she go to Phoenix? Would be a great fit for her.
See oldhusky above on characteristics of franchises that would be a good fit. Phoenix holds none of these. The change in management and coaching has previously been explored. The abstract or summary is historical management in recent years which has plumbed the depths of incompetence both in terms of team construction and coaching.
The upcoming year will be a dumpster fire. The GOAT is of course well past her prime and by insisting on playing insures high volume, low efficiency from her position as well as a strong possibility of limited service due to age-related injuries.
With her salary and that of BG there is little flexibility in terms of roster construction.
I would say 2024 will be a year of uncertainty for the Mercury but actually that's not true. The certainty is a 25 loss team in full disarray. It would be my expectation that the probable third pick in the draft will return for covid year at the college level. They will make more money and not be subjected to the stress of a laughably incompetent franchise and an aging Superstar who has missed the retired message.
Nneka is well aware of these issues and at this stage of her career doesn't want to go through the valley of rebuilding which for Phoenix appears to extend beyond the horizon.