They were initially saying it was to try & work together to get better marketshare in the Chinese EV market. I doubt that very much - it's about Nissan trying to not go under (they were <1.5 years away from closing their doors or being bought out by some tech conglomerate). IMO, Honda found a way to get them for cheap as they're very diligent about where they spend their $$$ (which is why they've made some of the motorsport decisions they have in recent years).
Chinese EVs have apparently skyrocketed in quality in recent years, and they're likely only going to get better. This is not surprising since China copies everything. They've historically *not* been good at copying mechanical things (at least automotive), but they *are* good with tech. And EVs are way more tech-based than they are mechanical-based now.
Part of me hopes the merger (which isn't happening until 2026) means we can get better performance cars (Civics are too big & would be better if AWD or RWD, the NSX was too expensive, the R35 ended up being insanely expensive, the 370 & Z were never as good as they should have been), but we'll see.
Also - Mitsubishi is apparently gonna be part of the deal, but just how remains to be seen. I've seen things saying that'll be a separate merger, but I have no idea.
Renault likely has to be part of the deal in some fashion, as they (from what I understand) have like 30-35% ownership in Nissan.